3-pyrrolidinylthio-1-azabicyclo(3.2.0)-hept-2-ene-2-carboxylic acid compounds

ABSTRACT

The present invention concerns intermediates in the preparation of novel 3-pyrrolidinylthio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid compounds and pharmaceutically acceptable salts thereof. The novel 3-pyrrolidinylthio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid compounds and pharmaceutically acceptable salts thereof show antimicrobial activity.

This is a division, of application Ser. No. 07/323,404, filed on Mar.14, 1989 now U.S. Pat. No. 4,925,838.

The present invention relates to novel3-pyrrolidinylthio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acidcompounds and pharmaceutically acceptable salts thereof.

More particularly, it relates to novel3-pyrrolidinylthio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acidcompounds and pharmaceutically acceptable salts thereof, which haveantimicrobial activity, to processes for the preparation thereof, to apharmaceutical composition comprising the same, and to a use of the sameas a medicament and in the treatment of infectious diseases in humanbeing or animal.

Accordingly, one object of the present invention is to provide novel3-pyrrolidinylthio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acidcompounds and pharmaceutically acceptable salts thereof, which arehighly active against a number of pathogenic microorganisms and areuseful as antimicrobial agents.

Another object of the present invention is to provide processes for thepreparation of novel3-pyrrolidinylthio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acidcompounds and salts thereof.

A further object of the present invention is to provide a pharmaceuticalcomposition comprising, as an active ingredient, said3-pyrrolidinylthio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acidcompounds and pharmaceutically acceptable salts thereof.

Still further object of the present invention is to provide a use ofsaid 3-pyrrolidinylthio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acidcompounds and pharmaceutically acceptable salts thereof as a medicamentand in the treatment of infectious diseases by pathogenic microorganismsin human being or animal.

The object3-pyrrolidinylthio-1-azabicyclo[3.2.0]-hept-2-ene-2-carboxylic acidcompounds are novel and can be represented by the following generalformula: ##STR1## in which R¹ is carboxy or protected carboxy,

R² is hydroxy(lower)alkyl or protected hydroxy(lower)alkyl,

R³ is hydrogen or lower alkyl,

R⁴ is aliphatic heterocyclic group which may be substituted by suitablesubstituent(s),

R⁵ is hydrogen, lower alkyl or imino-protective group, and

A is lower alkylene,

and pharmaceutically acceptable salts thereof.

Suitable pharmaceutically acceptable salts of the object compounds (I)are conventional non-toxic salts and may include a salt with a base suchas an inorganic base salt, for example, an alkali metal salt (e.g.sodium salt, potassium salt, etc.), an alkaline earth metal salt (e.g.calcium salt, magnesium salt, etc.), an ammonium salt, an organic basesalt, for example, an organic amine salt (e.g. triethylamine salt,pyridine salt, picoline salt, ethanolamine salt, triethanolamine salt,dicyclohexylamine salt, N,N'-dibenzylethylenediamine salt, etc.); a saltwith an acid such as inorganic acid addition salt (e.g. hydrochloride,hydrobromide, sulfate, phosphate, etc.), an organic acid addition salt(e.g. formate, acetate, trifluoroacetate, maleate, tartrate,methanesulfonate, benzenesulfonate, etc.); a salt with a basic or acidicamino acid (e.g. arginine, aspartic acid , glutamic acid, etc.); anintermolecular or intramolecular quarternary salt; and the like.

The said intermolecular quarternary salt can be formed when R⁵ is loweralkyl or the aliphatic heterocyclic group in R⁴ in the compound (I)contains tertiary nitrogen atom(s) (e.g. pyrrolidin-1-yl,piperazin-1-yl, etc.), and suitable intermolecular quaternary salt mayinclude 1-(lower)alkylpyrrolidinio (lower)alkylsulfate (e.g.1-methylpyrrolidinio methylsulfate, 1-ethylpyrrolidinio ethylsulfate,etc.), 1-(lower)alkylpyrrolidinio halide (e.g. 1-methylpyrrolidinioiodide, etc.), 1-carbamoyl(lower)alkylpyrrolidinio (lower)alkylsulfate(e.g. 1-carbamoylmethylpyrrolidinio methylsulfate,1-carbamoylethylpyrrolidinio ethylsulfate, etc.),1-carbamoyl(lower)alkylpyrrolidinio halide (e.g.1-carbamoylmethylpyrrolidinio iodide, 1-carbamoylethylpyrrolidinioiodide, etc.), 1-(lower)alkylpiperazinio (lower)alkylsulfate (e.g.1-methylpiperazinio methylsulfate, 1-ethylpiperazinio ethylsulfate,etc.), 1-(lower)alkylpiperazinio halide (e.g. 1-methylpiperazinioiodide, 1-ethylpiperazinio iodide, etc.), and the like.

The said intramolecular salt can be formed when the aliphaticheterocyclic group in R⁴ in the compound (I) contains tertiary nitrogenatom(s) (e.g. pyrrolidin-1-yl, piperazin-1-yl, etc.) and R² is carboxy,and suitable intramolecular salt may include 1-(lower)alkylpyrrolidiniocarboxylate (e.g. 1-methylpyrrolidinio carboxylate, 1-ethylpyrrolidiniocarboxylate, 1-propylpyrrolidinio carboxylate, 1-isopropylpyrrolidiniocarboxylate, 1-butylpyrrolidinio carboxylate, etc.),1-[carbamoyl(lower)alkyl]pyrrolidinio carboxylate (e.g.1-[carbamoylmethyl]pyrrolidinio carboxylate,1-[carbamoylethyl]pyrrolidinio carboxylate,1-[carbamoylpropyl]pyrrolidinio carboxylate,1-[carbamoylisopropyl]pyrrolidinio carboxylate,1-[carbamoylbutyl]pyrrolidinio carboxylate, etc.),1-(lower)alkylpiperazinio carboxylate (e.g. 1-methylpiperaziniocarboxylate, 1-ethylpiperazinio carboxylate, 1-propylpiperaziniocarboxylate, 1-isopropylpiperazinio carboxylate, 1-butylpiperaziniocarboxylate, etc.), and the like.

Further, said intramolecular salt can be formed when the nitrogen atomin the pyrrolidine moiety ##STR2## of the compound (I) has an additionalsubstituent and R is carboxy, and suitable example of such pyrrolidinemoiety may include 1,1-di(lower)alkyl-4-pyrrolidinio (e.g.1,1-dimethyl-4-pyrrolidinio, etc.),1-(lower)alkyl-1-carbamoyl(lower)alkyl-4-pyrrolidinio [e.g.1-(lower)alkyl-1-carbamoylmethyl-4-pyrrolidinio, etc.] and the like.

In the object compound (I) and the intermediary compounds mentionedbelow, it is to be understood that there may be one or morestereo-isomeric pair(s) such as optical isomers due to asymmetric carbonatom(s), and such isomers are also included within the scope of thepresent invention.

According to the present invention, the object compound (I) orpharmaceutically acceptable salts thereof can be prepared by theprocesses as illustrated by the following reaction schemes. ##STR3## inwhich R¹, R², R³, R⁴, R⁵ and A are each as defined above,

R_(a) ¹ is protected carboxy,

R_(a) ² is protected hydroxy(lower)alkyl,

R_(b) ² is hydroxy(lower)alkyl,

R_(a) ⁴ is aliphatic heterocyclic group substituted by protected amino,

R_(b) ⁴ is aliphatic heterocyclic group substituted by amino,

R_(c) ⁴ is protected piperazinyl whose ring carbon atom(s) may besubstituted by suitable substituent(s),

R_(d) ⁴ is piperazinyl whose ring carbon atom(s) may be substituted bysuitable substituent(s),

R_(a) ⁵ is imino-protective group,

R_(b) ⁵ is lower alkyl,

R⁶ is lower alkyl or carbamoyl(lower)alkyl,

X is an acid residue, and

a group of the formula: ##STR4## is N-containing aliphatic heterocyclicgroup which may be substituted by suitable substituent(s).

The compound (III) used in the process 1 is new and can be prepared, forexample, by the following method or a conventional manner. ##STR5## inwhich R⁴, R⁵ and A are each as defined above, and

R⁷ is mercapto-protective group.

In the above and subsequent descriptions of the present specification,suitable examples and illustrations of the various definitions which thepresent invention includes within the scope thereof are explained indetail as follows.

The term "lower" is intended to mean 1 to 6 carbon atom(s), unlessotherwise indicated.

Suitable "protected carboxy" may include esterified carboxy wherein"esterified carboxy" can be referred to the ones as mentioned below.

Suitable examples of the ester moiety of an esterified carboxy may bethe ones such as lower alkyl ester (e.g. methyl ester, ethyl ester,propyl ester, isopropyl ester, butyl ester, isobutyl ester, t-butylester, pentyl ester, hexyl ester, etc.) which may have at least onesuitable substituent(s), for example, lower alkanoyloxy(lower)alkylester [e.g. acetoxymethyl ester, propionyloxymethyl ester,butyryloxymethyl ester, valeryloxymethyl ester, pivaloyloxymethyl ester,hexanoyloxymethyl ester, 1-(or 2-)acetoxyethyl ester, 1-(or 2- or3-)acetoxypropyl ester, 1-(or 2- or 3- or 4-)acetoxybutyl ester, 1-(or2-)propionyloxyethyl ester, 1-(or 2- or 3-)propionyloxypropyl ester,1-(or 2-)butyryloxyethyl ester, 1-(or 2-)isobutyryloxyethyl ester, 1-(or2-)pivaloyloxyethyl ester, 1-(or 2-)hexanoyloxyethyl ester,isobutyryloxymethyl ester, 2-ethylbutyryloxymethyl ester,3,3-dimethylbutyryloxymethyl ester, 1-(or 2-)pentanoyloxyethyl ester,etc.], lower alkanesulfonyl(lower)alkyl ester (e.g. 2-mesylethyl ester,etc.), mono(or di or tri)halo(lower)alkyl ester (e.g. 2-iodoethyl ester,2,2,2-trichloroethyl ester, etc.); lower alkoxycarbonyloxy(lower)alkylester [e.g. methoxycarbonyloxymethyl ester, ethoxycarbonyloxymethylester, propoxycarbonyloxymethyl ester, t-butoxycarbonyloxymethyl ester,1-(or 2-)methoxycarbonyloxyethyl ester, 1-(or 2-)ethoxycarbonyloxyethylester, 1-(or 2-) isopropoxycarbonyloxyethyl ester, etc.],phthalidylidene(lower)alkyl ester, or (5-loweralkyl-2-oxo-1,3-dioxol-4-yl)(lower)alkyl ester [e.g.(5-methyl-2-oxo-1,3-dioxol-4-yl)methyl ester,(5-ethyl-2-oxo-1,3-dioxol-4-yl)methyl ester,(5-propyl-2-oxo-1,3-dioxol-4-yl)ethyl ester, etc.]; lower alkenyl ester(e.g. vinyl ester, allyl ester, etc.); lower alkynyl ester (e.g. ethynylester, propynyl ester, etc.); ar(lower)alkyl ester which may have atleast one suitable substituent(s) (e.g. benzyl ester, 4-methoxybenzylester, 4-nitrobenzyl ester, phenethyl ester, trityl ester, benzhydrylester, bis(methoxyphenyl)methyl ester, 3,4-dimethoxybenzyl ester,4-hydroxy-3,5-di-t-butylbenzyl ester, etc.); aryl ester which may haveat least one suitable substituent(s) (e.g. phenyl ester, 4-chlorophenylester, tolyl ester, t-butylphenyl ester, xylyl ester, mesityl ester,cumenyl ester, etc.); phthalidyl ester; and the like.

Preferable example of the protected carboxy thus defined may be loweralkenyloxycarbonyl and phenyl(or nitrophenyl)(lower)alkoxycarbonyl, morepreferable one may be C₂ -C₄ alkenyloxycarbonyl and phenyl(ornitrophenyl)-(C₁ -C₄)alkoxycarbonyl, and the most preferable one may be4-nitrobenzyloxycarbonyl and allyloxycarbonyl.

Suitable "hydroxy(lower)alkyl" may include straight or branched loweralkyl having hydroxy group such as hydroxymethyl, hydroxyethyl,hydroxypropyl, 1-(hydroxymethyl)ethyl, 1-hydroxy-1-methylethyl,hydroxybutyl, hydroxypentyl, hydroxyhexyl, and the like, in which morepreferable example may be hydroxy(C₁ -C₄)-alkyl and the most preferableone may be 1-hydroxyethyl.

Suitable "protected hydroxy(lower)alkyl" means aforementionedhydroxy(lower)alkyl, in which the hydroxy group is protected by aconventional hydroxy-protective group such as those mentioned in theexplanation of imino-protective group as mentioned below, preferablylower alkenyloxycarbonyl and phenyl(ornitrophenyl)-(lower)alkoxycarbonyl; (C₆ -C₁₀)ar(lower)alkyl such asmono- or di- or triphenyl-(lower)alkyl (e.g. benzyl, benzhydryl, trityl,etc.), etc.; trisubstituted silyl such as tri(lower)alkylsilyl (e.g.trimethylsilyl, triethylsilyl, isopropyldimethylsilyl,t-butyldimethylsilyl, diisopropylmethylsilyl, etc.), tri(C₆-C₁₀)arylsilyl (e.g. triphenylsilyl, etc.), tris[(C₆-C₁₀)ar(lower)alkyl]silyl, for example, tris[phenyl(lower)alkyl]silyl(e.g. tribenzylsilyl, etc.), etc.; and the like.

Preferable example of "protected hydroxy(lower)alkyl thus defined may be[phenyl(or nitrophenyl)(lower)alkoxy]-carbonyloxy(lower)alkyl and[tri(lower)alkylsilyl]oxy-(lower)alkyl, more preferable one may be[phenyl(or nitrophenyl)(C₁ -C₄)alkoxy]carbonyloxy(C₁ -C₄)alkyl and[tri(C₁ -C₄)alkylsilyl]oxy(C₁ -C₄)alkyl, and the most preferable one maybe 4-nitrobenzyloxycarbonyl.

Suitable "lower alkyl" may include straight or branched one such asmethyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl, and thelike, in which more preferable example may be C₁ -C₄ alkyl and the mostpreferable one may be methyl and ethyl.

Suitable aliphatic heterocyclic group moiety of "aliphatic heterocyclicgroup which may be substituted by suitable substituent(s)", "aliphaticheterocyclic group substituted by protected amino" or "aliphaticheterocyclic group substituted by amino" may include saturatedmonocyclic or polycyclic heterocyclic group containing at least onehetero-atom such as oxygen, sulfur or nitrogen atom.

Preferable aliphatic heterocyclic group moiety may be saturated, 3 to8-membered, more preferably 5 or 6-membered heteromonocyclic groupcontaining 1 to 4 nitrogen atom(s) and optionally 1 or 2 oxygen atom(s),for example, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, piperidyl,piperidino, piperazinyl, morpholinyl, morpholino, etc.,

wherein said aliphatic heterocyclic group may be substituted by one ormore, preferably one or two suitable substituent(s) such as amino;protected amino in which the amino-protective group may be the same asthose for the imino-protective group as mentioned below; carbamoyl;lower alkyl as mentioned above; oxo; lower alkylsulfonyl (e.g.methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl,butylsulfonyl, pentylsulfonyl, hexylsulfonyl, etc.); hydroxy(lower)alkylas mentioned above, in which the most preferable one may behydroxymethyl and 2-hydroxyethyl; carbamoyl(lower)alkyl as mentionedbelow; and the like. And further, the imino-moiety thereof may beprotected by a conventional imino-protective group as mentioned below.

Preferable example of "aliphatic heterocyclic group which may besubstituted by suitable substituent(s)" may be:

- imidazolidinyl (e.g. imidazolidin-1-yl, etc.);

- oxoimidazolidinyl (e.g. 2-oxoimidazolidin-1-yl, etc.);

- dioxoimidazolidinyl (e.g. 2,4-dioxoimidazolidin-1-yl,2,5-dioxoimidazolidin-1-yl, etc.);

- [(lower)alkylsulfonyl]oxoimidazolidinyl, more preferably [(C₁-C₄)alkylsulfonyl]oxoimidazolidinyl (e.g.3-methylsulfonyl-2-oxoimidazolidin-1-yl, etc.);

- piperazinyl (e.g. piperazin-1-yl, etc.);

- N-protected piperazinyl such as N-acylpiperazinyl, more preferablyN-phenyl(or nitrophenyl)-(C₁ -C₄)alkoxycarbonylpiperazinyl [e.g.4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl, etc.];

- (lower)alkylpiperazinyl, more preferably (C₁ -C₄)alkylpiperazinyl(e.g. 3-methylpiperazin-1-yl, 4-methylpiperazin-1-yl, etc.);

- N-protected (lower)alkylpiperazinyl such asN-acyl(lower)alkylpiperazinyl, more preferably N-phenyl(ornitrophenyl)(C )alkoxycarbonyl-(C₁ -C₄)alkylpiperazinyl [e.g.3-methyl-4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl, etc.];

- pyrrolidinyl (e.g. pyrrolidin-1-yl, etc.);

- aminopyrrolidinyl (e.g. 3-aminopyrrolidin-1-yl, etc.);

- protected aminopyrrolidinyl such as acylaminopyrrolidinyl, morepreferably phenyl(or nitrophenyl)(C₁ -C₄)alkoxycarbonylaminopyrrolidinyl[e.g. 3-(4-nitrobenzyloxycarbonylamino)-pyrrolidin-1-yl, etc.];

- carbamoylpyrrolidinyl (e.g. 2-carbamoylpyrrolidin-1-yl, etc.);

- piperidinyl (e.g. piperidin-1-yl, etc.);

- aminopiperidinyl (e.g. 4-aminopiperidin-1-yl, etc.);

- protected aminopiperidinyl such as acylaminopiperidinyl, morepreferably phenyl(or nitrophenyl)(C₁ -C₄)alkoxycarbonylaminopiperidinyl[e.g. 4-(4-nitrobenzyloxycarbonylamino)piperidin-1-yl, etc.];

- hydroxy(lower)alkylpyrrolidinyl, more preferably hydroxy(C₁-C₄)alkylpyrrolidinyl (e.g. 2-hydroxymethylpyrrolidin-1-yl, etc.);

- (lower)alkylpiperazinyl, more preferably (C₁ -C₄)-alkylpiperazinyl(e.g. 4-methylpiperazin-1-yl, etc.);

- carbamoylpiperazinyl (e.g. 4-carbamoylpiperazin-1-yl, etc.);

- oxopiperazinyl (e.g. 3-oxopiperazin-1-yl, etc.);

- morpholinyl (e.g. morpholino, etc.);

- [(lower)alkyl]oxoimidazolidinyl, more preferably [(C)alkyl]oxoimidazolidinyl [e.g. 3(or 4)-methyl-2-oxoimidazolidin-1-yl,3-ethyl-2-oxoimidazolidin-1-yl, etc.];

- [hydroxy(lower)alkyl]oxoimidazolidinyl, more preferably [hydroxy(C₁-C₄)alkyl]oxoimidazolidinyl [e.g.3-(2-hydroxyethyl)-2-oxoimidazolidin-1-yl, etc.].

Preferable example of "aliphatic heterocyclic group substituted byprotected amino" may be:

- protected aminopyrrolidinyl such as acylaminopyrrolidinyl, morepreferably phenyl(or nitrophenyl)(C₁ -C₄)alkoxycarbonylaminopyrrolidinyl[e.g. 3-(4-nitrobenzyloxycarbonylamino)pyrrolidin-1-yl, etc.];

- protected aminopiperidinyl such as acylaminopiperidinyl, morepreferably phenyl(or nitrophenyl)aminopiperidinyl [e.g.4-(4-nitrobenzyloxycarbonylamino)piperidin-1-yl, etc.]. Preferableexample of "aliphatic heterocyclic group substituted by amino" may be:

- aminopyrrolidinyl (e.g. 3-aminopyrrolidin-1-yl, etc.);

- aminopiperidinyl (e.g. 4-aminopiperidin-1-yl, etc.).

Suitable "protected piperazinyl whose ring carbon atom(s) may besubstituted by suitable substituent(s)" may include N-protectedpiperazinyl such as N-acylpiperazinyl, whose ring carbon atom(s) may besubstituted by one or more, more preferably, one or two suitablesubstituent(s) such as amino, protected amino as mentioned above,carbamoyl, lower alkyl as mentioned above, oxo, lower alkylsulfonyl asmentioned above, hydroxy(lower)alkyl as mentioned above,carbamoyl(lower)alkyl as mentioned above, and the like.

More preferable example of "protected piperazinyl whose ring carbonatom(s) may be substituted by suitable substituent(s)" may beN-phenyl(or nitrophenyl)(C₁ -C₄)-alkoxycarbonyl(C )alkylpiperazinyl[e.g. 3-methyl-4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl, etc.].

Suitable "piperazinyl whose ring carbon atom(s) may be substituted bysuitable substituent(s)" may include piperazinyl whose ring carbonatom(s) may be substituted by one or more, more preferably, one or twosuitable substituent(s) such as amino, protected amino as mentionedabove, carbamoyl, lower alkyl as mentioned above, oxo, loweralkylsulfonyl as mentioned above, hydroxy(lower)alkyl as mentionedabove, carbamoyl(lower)alkyl as mentioned above, and the like.

More preferable example of "piperazinyl whose ring carbon atom(s) may besubstituted by suitable substituent(s)" may be (C₁ -C₄)alkylpiperazinyl[e.g. 3-methylpiperazin-1-yl, etc.].

Suitable "imino-protective group" may include acyl such as aliphaticacyl, aromatic acyl, heterocyclic acyl and aliphatic acyl substitutedwith aromatic or heterocyclic group(s) derived from carboxylic,carbonic, sulfonic and carbamic acids.

The aliphatic acyl may include saturated or unsaturated, acyclic orcyclic ones, for example, alkanoyl such as lower alkanoyl (e.g. formyl,acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl,hexanoyl, etc.), alkylsulfonyl such as lower alkylsulfonyl (e.g. mesyl,ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl,isobutylsulfonyl, pentylsulfonyl, hexylsulfonyl, etc.), carbamoyl,N-alkylcarbamoyl (e.g. methylcarbamoyl, ethylcarbamoyl, etc.),alkoxycarbonyl such as lower alkoxycarbonyl (e.g. methoxycarbonyl,ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, t-butoxycarbonyl,etc.), alkenyloxycarbonyl such as lower alkenyloxycarbonyl (e.g.vinyloxycarbonyl, allyloxycarbonyl, etc.), alkenoyl such as loweralkenoyl (e.g. acryloyl, methacryloyl, crotonoyl, etc.),cycloalkanecarbonyl such as cyclo(lower)alkanecarbonyl (e.g.cyclopropanecarbonyl, cyclopentanecarbonyl, cyclohexanecarbonyl, etc.),and the like.

The aromatic acyl may include C₆ -C₁₀ aroyl (e.g. benzoyl, toluoyl,xyloyl, etc.), N-(C₆ -C₁₀)arylcarbamoyl (e.g. N-phenylcarbamoyl,N-tolylcarbamoyl, N-naphthylcarbamoyl, etc.), C₆ -C₁₀ arenesulfonyl(e.g. benzenesulfonyl, tosyl, etc.), and the like.

The aliphatic acyl substituted with aromatic group(s) may includearalkoxycarbonyl such as phenyl(lower)alkoxycarbonyl (e.g.benzyloxycarbonyl, phenethyloxycarbonyl, etc.), and the like.

These acyl groups may be further substituted with one or more suitablesubstituent(s) such as nitro, and the like, and preferable acyl havingsuch substituent(s) may be nitroaralkoxycarbonyl(e.g.nitrobenzyloxycarbonyl, etc.), and the like.

Preferable example of "imino-protective group" thus defined may be loweralkenyloxycarbonyl and phenyl(or nitrophenyl)(lower)alkoxycarbonyl, morepreferable one may be C₂ -C₄ alkenyloxycarbonyl and phenyl(ornitrophenyl)(C₁ -C₄)alkoxycarbonyl, and the most preferable one may be4-nitrobenzyloxycarbonyl.

Suitable "carbamoyl(lower)alkyl" may include straight or branched loweralkyl having carbamoyl group such as carbamoylmethyl, carbamoylethyl,carbamoylpropyl, 1-(carbamoylmethyl)ethyl, 1-carbamoyl-1-methylethyl,carbamoylbutyl, carbamoylpentyl, carbamoylhexyl, and the like, in whichmore preferable example may be carbamoyl(C₁ -C₄)alkyl and the mostpreferable one may be carbamoylmethyl.

Suitable "lower alkylene" may include straight or branched one such asmethylene, ethylene, trimethylene, tetramethylene, pentamethylene,hexamethylene, methylmethylene, ethylethylene, propylene, and the like,in which more preferable example may be C₁ -C₄ alkylene and the mostpreferable one may be methylene.

Suitable "acid residue" may include an inorganic acid residue such asazido, halogen (e.g. chlorine, bromine, fluorine or iodine), and thelike, an organic acid residue such as acyloxy (e.g. benzenesulfonyloxy,tosyloxy, methanesulfonyloxy, etc.), and the like, in which morepreferable example may be halogen and the most preferable one may beiodine.

Suitable "mercapto-protective group" may include acyl as mentionedabove, (C₆ -C₁₀)ar(lower)alkyl such as mono-or di- ortriphenyl(lower)alkyl (e.g. benzyl, phenethyl, benzhydryl, trityl,etc.), and the like, in which preferable example may be lower alkanoyl,C₆ -C₁₀ aroyl and triphenyl(lower)alkyl, more preferable one may be C₁-C₄ alkanoyl, C₆ -C₁₀ aroyl and triphenyl(C₁ -C₄)alkyl, and the mostpreferable one may be benzoyl, acetyl and trityl.

In the definition of a group of the formula: ##STR6## suitable"N-containing aliphatic heterocyclic group which may be substituted bysuitable substituent(s)" may include saturated 3 to 8 membered, morepreferably 5 or 6 membered, heteromonocyclic group containing 1 to 4nitrogen atom(s) and optionally 1 or 2 oxygen atom(s), for example,pyrrolidin-1-yl, imidazolidin-1-yl, pyrazolidin-1-yl, piperidino,piperazin-1-yl, morpholino, etc.,

wherein said aliphatic heterocyclic group may be substituted by one ormore, preferably one or two, suitable substituent(s) such as amino,protected amino as mentioned above, carbamoyl, lower alkyl as mentionedabove, oxo, lower alkylsulfonyl as mentioned above, hydroxy(lower)alkylas mentioned above, carbamoyl(lower)alkyl as mentioned above, and thelike. And further, in case that said aliphatic heterocyclic group isimidazolidin-1-yl, pyrazolidin-1-yl or piperazin-1-yl, the imino-moietythereof may be protected by a conventional imino-protective group asmentioned above.

Preferable example of "N-containing aliphatic heterocyclic group whichmay be substituted by suitable substituent(s)" thus defined may be:

- imidazolidin-1-yl;

- oxoimidazolidin-1-yl (e.g. 2-oxoimidazolidin-1-yl, etc.);

- dioxoimidazolidin-1-yl (e.g. 2,4-dioxoimidazolidin-1-yl, etc.);

- [(lower)alkylsulfonyl]oxoimidazolidin-1-yl, more preferably [(C₁-C₄)alkylsulfonyl]oxoimidazolidin. 1-yl (e.g.3-methylsulfonyl-2-oxoimidazolidin-1-yl, etc.)

- piperazin-1-yl;

- N-protected piperazin-1-yl such as N-acylpiperazin-1-yl, morepreferably N-phenyl(or nitrophenyl){C₁ -C₄)alkoxycarbonylpiperazin-1-yl[e.g. 4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl, etc.];

- (lower)alkylpiperazin-1-yl, more preferably (C₁-C₄)alkylpiperazin-1-yl (e.g. 3-methylpiperazin-1-yl,4-methylpiperazin-1-yl, etc.);

- N-protected (lower)alkylpiperazin-1-yl such asN-acyl(lower)alkylpiperazin-1-yl, more preferably N-phenyl(ornitrophenyl)(C₁ -C₄)alkoxycarbonyl-(C₁ -C₄)alkylpiperazin-1-yl [e.g.3-methyl-4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl, etc.];

- pyrrolidin-1-yl;

- aminopyrrolidin-1-yl (e.g. 3-aminopyrrolidin-1-yl, etc.);

- protected aminopyrrolidin-1-yl such as acylaminopyrrolidin-1-yl, morepreferably phenyl(or nitrophenyl)-(C₁-C₄)alkoxycarbonylaminopyrrolidin-1-yl [e.g.3-(4-nitrobenzyloxycarbonylamino)pyrrolidin-1-yl, etc.];

- carbamoylpyrrolidin-1-yl (e.g. 2-carbamoylpyrrolidin-1-yl, etc.);

- piperidin-1-yl;

- aminopiperidin-1-yl (e.g. 4-aminopiperidin-1-yl, etc.);

- protected aminopiperidin-1-yl such as acylaminopiperidin-1-yl, morepreferably phenyl(or 1 nitrophenyl)(C₁-C₄)alkoxycabonylaminopiperidin-1-yl [e.g.4-(4-nitrobenzyloxycarbonylamino)-piperidin-1-yl, etc.];

- hydroxy(lower)alkylpyrrolidin-1-yl, more preferably hydroxy(C₁-C₄)alkylpyrrolidin-1-yl (e.g. 2-hydroxymethylpyrrolidin-1-yl, etc.);

- (lower)alkylpiperazin-1-yl, more preferably (C₁-C₄)alkylpiperazin-1-yl (e.g. 4-methylpiperazin-1-yl, etc.);

- carbamoylpiperadin-1-yl (e.g. 4-carbamoylpiperazin-1-yl, etc.);

- oxopiperazin-1-yl (e.g. 3-oxopiperazin-1-yl, etc.);

- morpholino;

- [(lower)alkyl]oxoimidazolidin-1-yl, more preferably [(C₁-C₄)alkyl]oxoimidazolidin-1-yl [e.g. 3(or4)-methyl-2-oxoimidazolidin-1-yl, 3-ethyl-2-oxoimidazolidin-1-yl, etc.];

- [hydroxy(lower)alkyl]oxoimidazolidin-1-yl, more preferably [hydroxy(C₁-C₄)alkyl]oxoimidazolidin-1-yl [e.g.3-(2-hydroxyethyl)-2-oxoimidazolidin-1-yl, etc.].

The processes for the preparation of the object compound (I) of thepresent invention are explained in detail in the following

(1) Process 1 :

The compound (I) or salts thereof can be prepared by reacting thecompound (II) or a reactive derivative at the oxo group thereof or saltsthereof with the compound (III) or salts thereof.

Suitable salts of the compound (II) may be salts with bases such asthose given for the compound (I).

The reactive derivative at the oxo group of the compound (II) can berepresented by the following formula (II'), which is preferably used inthis reaction and can be prepared by reacting the compound (II) or saltsthereof with an acylating agent. ##STR7## in which R¹, R² and R³ areeach as defined above, and

R⁸ is acyl as exemplified for the imino-protective group and further0,0-substituted phosphono derived from, for example, organic phosphoricacid mentioned hereinbelow.

Suitable acylating agents may include conventional ones which canintroduce the acyl group as mentioned above into the compound (II), andpreferable acylating agents may be organic sulfonic or phosphoric acidor its reactive derivative such as acid halide, acid anhydride, and thelike, for example, arenesulfonyl halide (e.g. benzenesulfonyl chloride,p-toluenesulfonyl chloride, p-nitrobenzenesulfonyl chloride,p-bromobenzenesulfonyl chloride, etc.), arenesulfonic anhydride (e.g.benzenesulfonic anhydride, p-toluenesulfonic anhydride,p-nitrobenzenesulfonic anhydride, etc.), lower alkanesulfonyl halidewhich may have additional halogen (e.g. methanesulfonyl chloride,ethanesulfonyl chloride, trifluoromethanesulfonyl chloride, etc.), loweralkanesulfonic anhydride which may have halogen (e.g. methanesulfonicanhydride, ethanesulfonic anhydride, trifluoromethanesulfonic anhydride,etc.), di(lower)alkyl phosphorohaloridate (e.g. diethylphosphorochloridate, etc.), diaryl phosphorohaloridate (e.g. diphenylphosphorochloridate, etc.), and the like.

This acylation reaction is usually carried out in a conventional solventwhich does not adversely influence the reaction such as acetone,dioxane, acetonitrile, chloroform, dichloromethane,hexamethylphosphoramide, dichloroethane, tetrahydrofuran, ethyl acetate,dimethylsulfoxide, N,N-dimethylformamide, pyridine, etc., or a mixturethereof.

When the acylating agent is used in a free acid form or its salt form inthis reaction, the reaction is preferably carried out in the presence ofa conventional condensing agent such as carbodiimide compound [e.g.N,N'-diethylcarbodiimide, N,N'-diisopropylcarbodiimide,N,N'-dicyclohexylcarbodiimide,N-cyclohexyl-N'-morpholinoethylcarbodiimide,N-cyclohexyl-N'-(4-diethylaminocyclohexyl)carbodiimide,N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide, etc.];N,N'-carbonyldiimidazole, N,N'-carbonylbis(2-methylimidazole);keteneimine compound (e.g. pentamethyleneketene-N-cyclohexylimine,diphenylketene-N-cyclohexylimine, etc.); ethoxyacetylene;1-alkoxy-1-chloroethylene; ethyl polyphosphate; isopropylpolyphosphate;phosphorus oxychloride; phosphorus trichloride; thionyl chloride; oxalylchloride; a combination of triphenylphosphine with carbon tetrachlorideor diazenedicarboxylate; 2-ethyl-7-hydroxybenzisoxazolium salt;2-ethyl-5-(m-sulfophenyl)-isoxazolium hydroxide intramolecular salt;1-(p-chlorobenzenesulfonyloxy)-6-chloro-1H-benzotriazole; so-calledVilsmeier reagent prepared by the reaction of N,N-dimethylformamide withthionyl chloride, phosgene, phosphorus oxychloride, etc.; and the like.

This acylation reaction may be carried out in the presence of aninorganic or organic base such as an alkali metal bicarbonate (e.g.sodium bicarbonate, potassium bicarbonate, etc.), alkali metal carbonate(e.g. sodium carbonate, potassium carbonate, etc.), alkaline earth metalcarbonate (e.g. magnesium carbonate, calcium carbonate, etc.),tri(lower)alkylamine (e.g. trimethylamine, triethylamine,N,N-diisopropyl-N-ethylamine, etc.), pyridine compound [e.g. pyridine,picoline, lutidine, N,N-di(lower)alkylaminopyridine such asN,N-dimethylaminopyridine, etc.], quinoline, N-lower alkylmorpholine(e.g. N-methylmorpholine, etc.), N,N-di(lower)alkylbenzylamine (e.g.N,N-dimethylbenzylamine, etc.), alkali metal alkoxide (e.g. sodiummethoxide, sodium ethoxide, potassium butoxide, etc.), and the like.

The reaction temperature of this acylation reaction is not critical andthe reaction is usually carried out under from cooling to warming.

With regard to the compound (II), it is to be noted that the3,7-dioxo-1-azabicyclo[3.2.0]heptane ring system of the followingformula (IIA) is well known to lie to tautomeric relation with the3-hydroxy-7-oxo-1-azabicyclo[3.2.0]hept-2-ene ring system of thefollowing formula (IIB), and accordingly, it is to be understood thatboth of these ring systems are substantially the same. ##STR8##

The compound (II') or salts thereof can be used with or withoutisolation for the subsequent reaction with the compound (III) or saltsthereof.

Suitable salts of the compound (III) may be the same as those for thecompound (I) and silver salt.

The reaction of the compound (II) or its reactive derivative or saltsthereof with the compound (III) or salts thereof can be carried out inthe presence of an organic or inorganic base such as those given in theexplanation of the acylation reaction as stated above.

This reaction can be carried out in a conventional solvent which doesnot adversely influence the reaction such as those given in theexplanation of the acylation reaction.

The reaction temperature is not critical and the reaction is usuallycarried out under from cooling to warming.

Process 2 :

The compound (I-b) or salts thereof can be prepared by subjecting thecompound (I-a) or salts thereof to removal reaction of thecarboxy-protective group on R_(a) ¹.

Suitable salts of the compounds (I-a) and (I-b) may be the same as thosefor the compound (I).

The present reaction is usually carried out by a conventional methodsuch as hydrolysis, reduction, and the like.

(i) Hydrolysis :

Hydrolysis is preferably carried out in the presence of a base or anacid. Suitable base may include an alkalimetal hydroxide (e.g. sodiumhydroxide, potassium hydroxide, etc.), an alkaline earth metal hydroxide(e.g. magnesium hydroxide, calcium hydroxide, etc.), alkali metalhydride (e.g. sodium hydride, potassium hydride, etc.), alkaline earthmetal hydride (e.g. calcium hydride, etc.), alkali metal alkoxide (e.g.sodium methoxide, sodium ethoxide, potassium t-butoxide, etc.), analkali metal carbonate (e.g. sodium carbonate, potassium carbonate,etc.), and alkaline earth metal carbonate [e.g. magnesium carbonate,calcium carbonate, etc.), an alkali metal bicarbonate (e.g. sodiumbicarbonate, potassium bicarbonate, etc.), and the like.

Suitable acid may include an organic acid (e.g. formic acid, aceticacid, propionic acid, trifluoroacetic acid, benzenesulfonic acid,p-toluenesulfonic acid, etc.) and an inorganic acid (e.g. hydrochloricacid, hydrobromic acid, sulfuric acid, phosphoric acid, etc.). Theacidic hydrolysis using trifluoroacetic acid is usually accelerated byaddition of cation trapping agent (e.g. phenol, anisole, etc.).

In case that the hydroxy-protective group is tri(lower)alkylsilyl, thehydrolysis can be carried out in the presence of tri(lower)alkylammoniumhalide (e.g. tributylammonium fluoride, etc.).

This reaction is usually carried out in a conventional solvent whichdoes not adversely influence the reaction such as water,dichloromethane, alcohol (e.g. methanol, ethanol, etc.),tetrahydrofuran, dioxane, acetone, etc., or a mixture thereof. A liquidbase or acid can be also used as the solvent.

The reaction temperature is not critical and the reaction is usuallycarried out under from cooling to heating.

(ii) Reduction :

The reduction method applicable for this removal reaction may include,for example, reduction by using a combination of a metal (e.g. zinc,zinc amalgam, etc.) or a salt of chrome compound (e.g. chromouschloride, chromous acetate, etc.) and an organic or inorganic acid (e.g.acetic acid, propionic acid, hydrochloric acid, sulfuric acid, etc.);and conventional catalytic reduction in the presence of a conventionalmetallic catalyst such as palladium catalysts (e.g. spongy palladium,palladium black, palladium oxide, palladium on carbon, colloidalpalladium, palladium on barium sulfate, palladium on barium carbonate,palladium hydroxide on carbon, etc.), nickel catalysts (e.g. reducednickel, nickel oxide, Raney nickel, etc.), platinum catalysts (e.g.platinum plate, spongy platinum, platinum black, colloidal platinum,platinum oxide, platinum wire, etc.), and the like.

In case that the catalytic reduction is applied, the reaction ispreferably carried out around neutral condition.

This reaction is usually carried out in a conventional solvent whichdoes not adversely influence the reaction such as water, alcohol (e.g.methanol, ethanol, propanol, etc.), dioxane, tetrahydrofuran, aceticacid, buffer solution (e.g..phosphate buffer, acetate buffer, etc.), andthe like, or a mixture thereof.

The reaction temperature is not critical and the reaction is usuallycarried out under from cooling to warming.

In case that the carboxy-protective group is allyl group, it can bedeprotected by hydrogenolysis using a palladium compound.

Suitable palladium compound used in this reaction may be palladium oncarbon, palladium hydroxide on carbon, palladium chloride, apalladium-ligand complex such astetrakis(triphenylphosphine)palladium(0),bis(dibenzylideneacetone)palladium(0), di[1,2-bis(diphenylphosphino)ethane]palladium(0), tetrakis(triphenylphosphite)palladium(0), tetrakis(triethyl phosphite)-palladium(0), andthe like.

The reaction can preferably be carried out in the presence of ascavenger of allyl group generated in situ, such as amine (e.g.morpholine, N-methylaniline, etc.), an activated methylene compound(e.g. dimedone, benzoylacetate, 2-methyl-3-oxovaleric acid, etc.), acyanohydrin compound (e.g. α-tetrahydropyranyloxybenzyl cyanide, etc.),lower alkanoic acid or a salt thereof (e.g. formic acid, acetic acid,ammonium formate, sodium acetate, sodium 2-ethylhexanoate, etc.),N-hydroxysuccinimide, and the like.

This reaction can be carried out in the presence of a base such as loweralkylamine (e.g. butylamine, triethyamine, etc.), pyridine, and thelike.

When palladium-ligand complex is used in this reaction, the reaction canpreferably be carried out in the presence of the corresponding ligand(e.g. triphenylphosphine, triphenyl phosphite, triethyl phosphite,etc.).

This reaction is usually carried out in a conventional solvent whichdoes not adversely influence the reaction such as water, methanol,ethanol, propanol, dioxane, tetrahydrofuran, acetonitrile, chloroform,dichloromethane, dichloroethane, ethyl acetate, etc., or a mixturethereof.

The removal reaction can be selected according to the kind ofcarboxy-protective group to be removed.

In this reaction, in case that R⁴ of the starting compound (I-a) is anintermolecular salt, then the object compound (I-b) can also be obtainedas its intramolecular salt.

The present process includes within the scope thereof a case that thehydroxy- and/or imino- and/or amino-protective group(s) on R² and/or R⁴,and/or imino-protective group of R⁵ are removed at the same time duringthe reaction.

(3) Process 3 :

The compound (I-d) or salts thereof can be prepared by subjecting thecompound (I-c) or salts thereof to removal reaction of theimino-protective group on R_(a) ⁵.

Suitable salts of the compounds (I-c) and (I-d) may be the same as thosefor the compound (I).

This reaction is usually carried out by a conventional method such ashydrolysis, reduction and the like.

The method of hydrolysis and reduction, and the reaction conditions(e.g. reaction temperature, solvent, etc.) are substantially the same asthose illustrated for removal reaction of the carboxy-protective groupof the compound (I-a) in Process 2, and therefore are to be referred tosaid explanation.

The present process includes within the scope thereof a case that thecarboxy- and/or imino- and/or amino-protective group(s) on R¹ and/or R⁴and/or hydroxy-protective group of R² are removed at the same timeduring the reaction.

(4) Process 4 :

The compound (I-f) or salts thereof can be prepared by subjecting thecompound (I-e) or salts thereof to removal reaction of thehydroxy-protective group on R_(a) ².

Suitable salts of the compounds (I-e) and (I-f) may be the same as thosefor the compound (I).

This reaction is usually carried out by a conventional method such ashydrolysis, reduction, and the like.

The method of hydrolysis and reduction, and the reaction conditions(e.g. reaction temperature, solvent, etc.) are substantially the same asthose illustrated for removal reaction of the carboxy-protective groupof the compound (I-a) in Process 2, and therefore are to be referred tosaid explanation.

In case that the hydroxy-protective group is tri(lower)alkylsilyl, theremoval of this protective group can also be carried out in the presenceof tetra(lower)alkylammonium fluoride (e.g. tetrabutyl-ammoniumfluoride, etc.).

The present process includes within the scope thereof a case that thecarboxy- and/or hydroxy- and/or imino-and/or amino-protective group(s)on R¹ and/or R² and/or R⁴ are removed at the same time during thereaction.

(5) Process 5 :

The compound (I-h) or salts thereof can be prepared by subjecting thecompound (I-g) or salts thereof to removal reaction of theamino-protective group on R_(a) ⁴.

Suitable salts of the compound (I-h) may be the same as those for thecompound (I).

Suitable salts of the compound (I-g) may be salts with bases such asthose given for the compound (I).

This reaction is usually carried out by a conventional method such ashydrolysis, reduction, and the like.

The method of hydrolysis and reduction, and the reaction conditions(e.g. reaction temperature, solvent, etc.) are substantially the same asthose illustrated for removal reaction of the carboxy-protective groupof the compound (I-a) in Process 2, and therefore are to be referred tosaid explanation.

The present process includes within the scope thereof a case that thecarboxy- and/or hydroxy- and/or imino-protective group(s) on R¹ and/orR² and/or R_(a) ⁴, and/or the imino-protective group of R⁵ are removedat the same time during the reaction.

(6) Process 6 :

The compound (I-j) or salts thereof can be prepared by reacting thecompound (I-i) or salts thereof with the compound (IV).

Suitable salts of the compounds (I-i) and (I-j) may be the same as thosefor the compound (I).

This reaction is usually carried out in a conventional solvent whichdoes not adversely influence the reaction such as water, dioxane,tetrahydrofuran, acetone, etc., or a mixture thereof.

The reaction temperature is not critical, and the reaction is usuallycarried out under from cooling to warming.

(7) Process 7 :

The compound (I-() or salts thereof can be prepared by subjecting thecompound (I-k) or salts thereof to removal reaction of theimino-protective group on R_(c) ⁴.

Suitable salts of the compounds (I-k) and (I-l) may be the same as thosefor the compound (I).

The reaction is usually carried out by a conventional method such ashydrolysis, reduction, and the like.

The method of hydrolysis and reduction, and the reaction conditions(e.g. reaction temperature, solvent, etc.) are substantially the same asthose illustrated for removal reaction of the carboxy-protective groupof the compound (I-a) in Process 2, and therefore are to be referred tosaid explanation.

The present process includes within the scope thereof a case that thecarboxy- and/or hydroxy- and/or amino-protective group(s) on R¹ and/orR² and/or R_(c) ⁴, and/or the imino-protective group of R⁵ are removedat the same time during the reaction.

(8) Process 8 :

The compound (I-n) or salts thereof can be prepared by reacting thecompound (I-m) or salts thereof with the compound (IV).

Suitable salts of the compounds (I-m) and (I-n) may be the same as thosefor the compound (I-a).

This reaction is usually carried out in a conventional solvent whichdoes not adversely influence the reaction such as water, dioxane,tetrahydrofuran, acetone, etc., or a mixture thereof.

The reaction temperature is not critical, and the reaction is usuallycarried out under from cooling to warming.

The object compounds (I), (I-b), (I-d), (I-f), (I-h), (I-j), (I-l) and(I-n) obtained according to the Processes 1 to 8, can be isolated andpurified in a conventional manner, for example, extraction,precipitation, fractional crystallization, recrystallization,chromatography, and the like.

Method A for preparing the new starting compound (III) or salts thereofis explained in detail in the following.

Method A

The compound (III) or salts thereof can be prepared by subjecting thecompound (III-a) or salts thereof to removal reaction of themercapto-protective group.

Suitable salts of the compound (III-a) may be the same as those for thecompound (III).

This removal reaction can be carried out by a conventional method asdescribed below, which can be selected according to the kind ofmercapto-protective group to be removed.

In case that the protective groups may be ar(lower)-alkyl group, it cangenerally be removed by treating, for example, with a silver compound(e.g. silver nitrate, silver carbonate, etc.), or reacting with amercapto compound (e.g. 2-mercaptoethanol, etc.) in the presence of anacid (e.g. trifluoroacetic acid, etc.).

The reaction with the silver compound as stated above is preferablycarried out in the presence of an organic base (e.g. pyridine, etc.).

The resultant silver salt of compound (III) can be transformed into itsalkalimetal salt, if necessary, by reacting with alkali metal halide(e.g. sodium iodide, potassium iodide, etc.).

Further, in case that the protective groups may be acyl group, it cangenerally be removed by solvolysis such as hydrolysis using an acid orbase, alcoholysis using a base, and the like.

Suitable acid or base used in these reactions may be the same such asthose given in the explanation of hydrolysis of the Process 2.

The reaction is usually carried out in a conventional solvent which doesnot adversely influence the reaction such as water, alcohol (e.g.methanol, ethanol, etc.), pyridine, N,N-dimethylformamide, etc., or amixture thereof, and further in case that the base or acid to be used isin liquid, it can also be used as a solvent.

The alcoholysis is usually carried out in a conventional alcohol such asmethanol, ethanol, and the like.

The reaction temperature is not critical and the reaction is usuallycarried out under from cooling to warming.

The object compound (I) and pharmaceutically acceptable salts thereof ofthe present invention are novel and exhibit high antimicrobial activity,inhibiting the growth of a wide variety of pathogenic microorgamismsincluding Gram-positive and Gram-negative microorganisms and are usefulas antimicrobial agents.

In the present invention, the object compound (I) possessing more potentantimicrobial activity can be represented by the following formula:##STR9##

in which R_(b) ², R³, R⁴ and A are each as defined above, andpharmaceutically acceptable salts thereof.

Particularly, the compound (I) possessing the most potent antimicrobialactivity can be represented by the following formula: ##STR10##

in which R³, R⁴ and A are each as defined above, and pharmaceuticallyacceptable salts thereof.

Now in order to show the utility of the object compound (I), the testdata on antimicrobial activity of the representative compound of thecompound (I) of this invention is shown in the following.

in vitro Antimicrobial Activity

Test Method :

in vitro Antimicrobial Activity was determined by the two-foldagar-plate dilution method as described blow.

One loopful of an overnight culture of a test strain in Trypticase-soybroth (10⁶ viable cells per ml) was streaked on heart infusion agar(HI-agar) containing graded concentrations of the test compound, and theminimal inhibitory concentration (MIC) was expressed in terms of μg/mlafter incubation at 37° C. for 20 hours.

Test Compound :

The compound of Example 2.

    ______________________________________                                        Test Result:                                                                  Test Strain     MIC (μg/ml)                                                ______________________________________                                        P. aeruginosa 26                                                                              0.39                                                          ______________________________________                                    

For therapeutic administration, the object compound (I) and thepharmaceutically acceptable salts thereof of the present invention areused in the form of conventional pharmaceutical preparation whichcontains said compound, as an active ingredient, in admixture withpharmaceutically acceptable carriers such as an organic or inorganicsolid or liquid excipient which is suitable for oral, parenteral andexternal administration. The pharmaceutical preparations may be in solidform such as tablet, granule, powder, capsule, or liquid form such assolution, suspension, syrup, emulsion, lemonade, and the like.

If needed, there may be included in the above preparations auxiliarysubstances, stabilizing agents, wetting agents and other commonly usedadditives such as lactose, stearic acid, magnesium stearate, terra alba,sucrose, corn starch, talc, gelatin, agar, pectin, peanut oil, oliveoil, cacao butter, ethylene glycol, tartaric acid, citric acid, fumaricacid, and the like.

While the dosage of the compound (I) may vary from and also depend uponthe age, conditions of the patient, a kind of diseases, a kind of thecompound (I) to be applied, etc. In general, amount between 1 mg andabout 4,000 mg or even more per day may be administered to a patient. Anaverage single dose of about 1 mg, 10 mg, 50 mg, 100 mg, 250 mg, 500 mg,1000 mg, 2000 mg, of the object compound (I) of the present inventionmay be used in treating diseases infected by pathogenic microorganisms.

The following Preparations and Examples are given for the purpose ofillustrating this invention in more detail.

Preparation 1

To a solution of(2S,4S)-4-acetylthio-2-hydroxymethyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(15 g) in a mixture of methanol (150 ml) and tetrahydrofuran (150 ml)was added a 28% solution of sodium methoxide in methanol (8.95 ml) underice-cooling and the mixture was stirred at the same temperature for 10minutes. To the mixture was added triphenylmethyl chloride (12.39 g) onice-bath, followed by stirring at the same temperature for 1 hour. Theprecipitates were filtered off and the filtrate was evaporated in vacuoto give a residue. The residue was dissolved in ethyl acetate (200 ml),washed with water, dried over magnesium sulfate, and concentrated underreduced pressure to give a syrup. The syrup was chromatographed onsilica gel (200 g) eluting with a mixture of dichloromethane and acetone(9:1 V/V). The fractions containing the desired compound were collectedand evaporated in vacuo to give(2S,4S)-2-hydroxymethyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(22.24 g).

NMR (CDCl₃, δ) : 1.25-1.75 (2H, m), 5.15 (2H, s), 7.10-7.65 (17H, m),8.28 (2H, d, J=9 Hz)

Preparation 2

To a solution of(2S,4S)-2-hydroxymethyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(10.7 g) in dichloromethane (100 ml) were added methanesulfonyl chloride(1.44 ml) and triethylamine (3.06 ml) under ice-cooling, and the mixturewas stirred at the same temperature for 1 hour. The reaction mixture waswashed with saturated aqueous sodium chloride, dried over magnesiumsulfate and evaporated in vacuo to give a residue. The residue waschromatographed on silica gel (150 g) eluting with a mixture ofdichloromethane and acetone (40:1 V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4S)-2-(methanesulfonyloxy)-methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(10.39 g).

NMR (CDCl₃, δ) : 2.60-2.90 (2H, m), 2.92 (3H, s), 5.10-5.35 (2H, s),7.15-7.60 (17H, m), 8.22 (2H, d, J=9 Hz)

Preparation 3-1)

To a solution of(2S,4S)-2-(methanesulfonyloxy)-methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(5.0 g) in dimethylformamide (90 ml) was added piperazine (2.0 g) andthe mixture was stirred at 80°_(]90)° C. for 5 hours. The reactionmixture was poured into ice-water (300 ml) and extracted twice withethyl acetate (200 ml). The extract was washed with saturated aqueoussodium chloride, dried over magnesium sulfate and evaporated in vacuo.The resulting residue was chromatographed on silica gel (150 g) elutingwith a mixture of chloroform and methanol (9:1 V/V). The fractionscontaining the desired compound were collected and evaporated in vacuoto give(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(piperazin-1-yl)methyl-4-(triphenylmethylthio)pyrrolidine(2.52 g).

NMR (CDCl₃ δ) : 1.83 (2H, s), 2.10-2.63 (7H, m), 2.65-3.03 (7H, m),3.66-3.98 (1H, m), 5.06-5 55 (2H, m), 7.05-7.66 (17H, m), 8.25 (2H, d,J=9 Hz)

Preparation 3-2)

To a solution of(2S,4S)-2-(methanesulfonyloxy)-methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(3.0 g) in dimethylformamide (30 ml) was added(2S)-2-carbamoylpyrrolidine (10.76 g) and the mixture was stirred at100°-110° C. for 5 hours. The reaction mixture was poured into ice-water(100 ml). The resulting precipitates were collected by filtration andwashed with water (100 ml). The precipitates were dissolved in ethylacetate (80 ml) and the solution was washed with aqueous sodiumchloride, dried over anhydrous magnesium sulfate and evaporated in vacuoto give a residue. The residue was chromatographed on silica gel (100 g)eluting with a mixture of dichloro-methane and acetone (9:1 V/V). Thefractions containing the desired compound were collected and evaporatedin vacuo to give (2S ,4S)-2-[(2S)-2-carbamoylpyrrolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(0.78 g).

NMR (CDCl₃, δ) : 5.06-5.33 (2H, m), 5.39-5.65 (1H, m), 7.05-7.67 (17H,m), 8.28 (2H, d, J=9 Hz)

Preparation 3-3)

(2S,4S)-2-[(3S)-3-(t-Butoxycarbonylamino)pyrrolidin-1-yl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidinewas obtained in 31.2% yield in substantially the same manner as that ofPreparation 3-1).

NMR (CDCl₃, δ) : 1.45 (9H, s), 5.11 (2H, s), 7.18-7.60 (17H, m), 8.24(2H, d, J=8 Hz)

Preparation 3-4)

(2S,4S)-1-(4-Nitrobenzyloxycarbonyl)-2-(pyrrolidin-1-yl)-methyl-4-(triphenylmethylthio)pyrrolidinewas obtained in 78.2% yield in substantially the same manner as that ofPreparation 3-1).

Preparation 3-5)

(2S,4S)-2-[(4-Hydroxypiperizin-1-yl)methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)-pyrrolidinewas obtained in 43.9% yield in substantially the same manner as that ofPreparation 3-1).

IR (Nujol) : 1710-1690, 1605, 1520 cm⁻¹

NMR (CDCl₃, δ) 1.70-2.35 (2H, m), 2.60-3.15 (2H, m), 3.53-4.06 (3H, m),5.15 (2H, s), 7.00-7.68 (17H, m), 8.28 (2H, d, J=9 Hz)

Preparation 3-6)

(2S,4S)-2-[(3-Methylpiperazin-1-yl)methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidinewas obtained in 90.1% yield in substantially the same manner as that ofPreparation 3-1).

NMR (CDCl₃, δ) : 1.02 (3H, d, J=6 Hz), 3.50-4.00 (2H, m), 5.10 (2H, s),7.07-7.67 (17H, m), 8.25 (2H, d, J=9 Hz)

Preparation 3-7)

To a solution of(2S,4S)-2-(methanesulfonyloxy)-methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(10.37 g) in dimethylformamide (100 ml) was added N-methylpiperazine(5.45 ml) and the mixture was stirred at 80°-90° C. for 5 hours. Thereaction mixture was poured into ice-water (300 ml) and extracted twicewith ethyl acetate (200 ml). The extract was washed with saturatedaqueous sodium chloride, dried over magnesium sulfate and evaporated invacuo. The resulting residue was chromatographed on silica gel (150 g)eluting with a mixture of chloroform and methanol (9:1 V/V). Thefraction containing the desired compound were collected and evaporatedin vacuo to give (2S ,4S) 2-(4-methylpiperazin-1-yl)-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine (6.87 g).

NMR (CDCl₃, δ) : 1.60-1.98 (1H, m), 2.22 (3H, s), 3.52-4.06 (1H, m),5.00-6.53 (2H, m), 6.95-7.60 (17H, m), 8.16 (2H, d, J=8 Hz)

Preparation 4

A solution of(2S,4S)-2-[(3S)-3-t-butoxycarbonylaminopyrrolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(2.14 g) in a mixture of trifluoroacetic acid (10 ml) and anisole (1 ml)was stirred on ice-bath for 1 hour. The reaction mixture was evaporatedin vacuo to give a residue. The residue was dissolved in ethyl acetate(100 ml) and the solution was washed with saturated aqueous sodiumhydrogen carbonate (50 ml) and saturated aqueous sodium chloride, driedover magnesium sulfate, and evaporated in vacuo to give a residue of(2S,4S)-2-[(3S)-3-aminopyrrolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine.To a solution of the residue in a mixture of ethyl acetate (40 ml) andwater (20 ml) was dropwise added a soluiton of 4-nitrobenzyloxycarbonylchloride (1.06 g) in tetrahydrofuran (10 ml) under ice-cooling, keepingthe pH between 8 and 9 with 1N aqueous sodium hydroxide solution. Themixture was stirred at the same temperature for 1 hour. To the reactionmixture was added ethyl acetate (50 ml). The solution was washed withsaturated aqueous sodium chloride, dried over magnesium sulfate andevaporated in vacuo to give a residue. The residue was chromatographedon silica gel (100 g) eluting with a mixture of dichloromethane andacetone (9:1 V/V). The fractions containing the desired compound werecollected and evaporated in vacuo to give(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-[(3S)-3-(4-nitrobenzyloxycarbonylamino)pyrrolidin-1-yl]methyl-4-(triphenylmethylthio)pyrrolidine(1.89 g).

IR (Nujol): 1710-1690, 1600, 1520, 1345 cm⁻¹

NMR (CDCl₃, δ): 1.45-1.96 (4H, m), 2.00-3.03 (10H, m), 3.55-3.90 (1H,m), 4.00-4.40 (1H, m), 5.06-5.38 (4H, m), 7.10-7.65 (19H, m), 8.24 (4H,d, J=8 Hz)

Preparation 5

To a solution of(2S,4S)-2-[(4-hydroxypiperizin-1-yl)methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(5.4 g) and triethylamine (1.54 ml) in dichloromethane (60 ml) was addedmethanesulfonyl chloride (0.72 ml) under ice-cooling and the mixture wasstirred under the same condition for 1 hour. The reaction mixture waswashed successively with aqueous sodium hydrogen carbonate and aqueoussodium chloride, dried over magnesium sulfate, and evaporated in vacuoto give(2S,4S)-2-[(4-methanesulfonyloxypiperizin-1-yl)-methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(6.06 g).

NMR (CDCl₃, δ): 3.00 (3H, s), 5.10-5.30 (2H, m), 7.13-7.66 (17H, m),8.27 (2H, d, J=9 Hz)

Preparation 6

A solution of(2S,4S)-2-[(4-methanesulfonyloxypiperizin-1-yl)methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(4.38 g) and sodium azide (1.19 g) in N,N-dimethylformamide (40 ml) wasstirred at 90°-100° C. for 2 hours. The reaction mixture was poured intoice-water (300 ml) and extracted 3 times with saturated aqueous sodiumchloride, dried over magnesium sulfate, and evaporated in vacuo. Theresulting residue was chromatographed on silica gel (150 g) eluting witha mixture of dichloromethane and acetone (10:1 V/V). The fractionscontaining the desired compound were collected and evaporated in vacuoto give(2S,4S)-2-[(4-azidopiperizin-1-yl)methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(2.51 g).

IR (Neat): 2110, 1700, 1525 cm⁻¹

NMR (CDCl₃, δ): 5.05-5.30 (2H, m), 7.20-7.65 (17H, m), 8.28 (2H, d, J=8Hz)

Preparation 7

To a solution of (2S,4S)2-[(4-azidopiperizin-1-yl)-methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(3.76 g) in pyridine (12 ml) was added triphenylphosphine (2.38 g) andthe mixture was stirred at ambient temperature for 1 hour. To thereaction mixture was added conc. ammonia (0.76 ml) and the mixture wasallowed to stand overnight at ambient temperature. The reaction mixturewas concentrated under reduced pressure and the residue was dissolved inethyl acetate (100 ml). The solution was washed with saturated aqueoussodium chloride, dried over magnesium sulfate and evaporated in vacuo togive a residue. The residue was chromatographed on silica gel (100 g)eluting with a mixture of chloroform and methanol (10:1 V/V). Thefractions containing the desired compound were collected and evaporatedin vacuo to give(2S,4S)-2-[(4-aminopiperizin-1-yl)methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(2.66 g).

NMR (CDCl₃, δ): 3.60-4.06 (2H, m), 5.03-5.28 (2H, m), 7.06-7.63 (17H,m), 8.25 (2H, d, J=9 Hz)

Preparation 8-1)

To a solution of(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(piperazin-1-yl)methyl-4-(triphenylmethylthio)-pyrrolidine(2.51 g) and triethylamine (0.73 ml) in dichloromethane (25 ml) wasadded 4-nitrobenzyloxycarbonyl chloride (0.91 g) under ice-cooling andthe mixture was stirred at the same temperature for 1 hour. The reactionmixture was washed with saturated aqueous sodium chloride, dried overmagnesium sulfate and evaporated in vacuo to give a residue. The residuewas chromatographed on silica gel (100 g) eluting with a mixture ofdichloromethane and acetone (20:1 V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-[4-(4-nitrobenzyloxycarbonyl)-piperazin-1-yl]methyl-4-(triphenylmethylthio)pyrrolidine(2.77 g).

IR (Nujol): 1690, 1605, 1520, 1345, 1240 cm⁻¹

NMR (CDCl₃, δ): 5.05-5.35 (4H, m), 7.10-7.60 (19H, m), 8.26 (4H, d, J=4Hz)

Preparation 8-2)

(2S ,4S)2-[{4-(4-Nitrobenzyloxycarbonylamino)-piperizin-1-yl}methyl]-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidinewas obtained in 95.8% yield in substantially the same manner as that ofPreparation 8-1).

NMR (CDCl₃, δ): 1.20-1.64 (2H, m), 4.66-4.83 (1H, m), 5.06-5.40 (4H, m),7.10-7.68 (19H, m), 8.22 (4H, d, J=9 Hz)

Preparation 8-3)

(2S,4S)-2-[3-Methyl-4-(4-nitrobenzyloxycarbonyl)-piperazin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidinewas obtained in 75.5% yield in substantially the same manner as that ofPreparation 8-1).

NMR (CDCl₃, δ): 1.10-1.43 (3H, m), 5.08 (2H, s), 5.21 (2H, s), 7.00-7.66(17H, m), 8.14 (4H, d, J=9 Hz)

Preparation 9-1)

To a solution of(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-[4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl]methyl-4-(triphenylmethylthio)pyrrolidine(2.76 g) in trifluoroacetic acid (15 ml) was added 2-mercaptoethanol(0.31 ml) under ice-cooling and the mixture was stirred at ambienttemperature for 10 minutes. The reaction mixture was concentrated underreduced pressure to give a residue. The residue was dissolved in toluene(20 ml) and the solution was evaporated in vacuo to give a syrup. Thesyrup was dissolved in ethyl acetate (60 ml) and washed successivelywith saturated aqueous sodium hydrogen carbonate (30 ml) and saturatedaqueous sodium chloride, dried over magnesium sulfate, and concentratedunder reduced pressure to give a residue. The residue waschromatographed on silica gel (100 g) eluting with a mixture ofdichloromethane and acetone (9:1 V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4S)-4-mercapto-1-(4-nitrobenzyloxycarbonyl)-2-[4-(4-nitrobenzyloxycarbonyl)-piperazin-1-yl]methylpyrrolidine(0.93 g).

IR (Neat): 1710-1690, 1610, 1520, 1350, 1245 cm⁻¹

NMR (CDCl₃, δ): 1.60-2.08 (2H, m), 2.30-3.00 (7H, m), 3.03-3.65 (6H, m),3.85-4.20 (2H, m), 5:24 (4H, s), 7.50 (4H, d, J=8 Hz), 8.25 (4H, d, J=8Hz)

Preparation 9-2)

To a solution of(2S,4S)-2-[(2S)-2-carbamoylpyrrolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(1.76 g) in trifluoroacetic acid (10 ml) was added 2-mercaptoethanol(0.38 ml) under ice-cooling and the mixture was stirred at ambienttemperature for 15 minutes. The reaction mixture was concentrated underreduced pressure to give a residue. The residue was dissolved in toluene(10 ml) and the solution was evaporated in vacuo. The resulting residuewas dissolved in ethyl acetate (50 ml), washed successively withsaturated aqueous sodium hydrogen carbonate (20 ml) and saturatedaqueous sodium chloride, dried over anhydrous magnesium sulfate, andevaporated in vacuo to give a residue. The residue was chromatographedon silica gel (100 g) eluting with a mixture of dichloromethane andacetone (9:1 V/V). The fractions containing the desired compound werecollected and evaporated in vacuo to give(2S,4S)-2-[(2S)-2-carbamoylpyrrolidin-1-yl]methyl-4-mercapto-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine(0.58 g).

IR (Neat): 1690-1680, 1610, 1525, 1430, 1410, 1350 cm⁻¹

NMR (CDCl₃, δ): 1.43-1.96 (4H, m), 3.80-4.22 (2H, m), 5.16 (2H, s),5.36-5.56 (1H, m), 7.50 (2H, d, J=9 Hz), 8.22 (2H, d, J=9 Hz)

Preparation 9-3)

(2S,4S)-4-Mercapto-1-(4-nitrobenzyloxycarbonyl-2-[(3S)-3-(4-nitrobenzyloxycarbonylamino)pyrrolidin-1-yl]-methylpyrrolidinewas obtained in 55.9% yield in substantially the same manner as that ofPreparation 9-1).

NMR (CDCl₃, δ): 5.23 (4H, s), 7.57 (4H, d, J=9 Hz), 8.28 (4H, d, J=9 Hz)

Preparation 9-4)

(2S,4S)-4-Mercapto-1-(4-nitrobenzyloxycarbonyl)-2-(pyrrolidin-1-yl)methylpyrrolidinewas obtained in 67.7% yield in substantially the same manner as that ofPreparation 9-1).

NMR (CDCl₃, δ): 1.80-2.35 (6H, m), 5.23 (2H, s), 7.53 (2H, d, J=8 Hz),8.26 (2H, d, J=8 Hz)

Mass: 365 (M⁺)

Preparation 9-5)

(2S,4S)-4-Mercapto-2-[{4-(4-nitrobenzyloxycarbonylamino)piperizin-1-yl}methyl]-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 31.6% yield in substantially the same manner as that ofPreparation 9-1).

NMR (CDCl₃, δ): 4.60-4.90 (1H, m), 5.13-5.28 (4H, m), 7.52 (4H, d, J=9Hz), 8.25 (4H, d, J=9 Hz)

Preparation 9-6)

(2S,4S)-4-Mercapto-2-[3-methyl-4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 50.9% yield in substantially the same manner as that ofPreparation 9-1).

IR (Neat) 1710-1690, 1610, 1525, 1220 cm⁻¹

NMR (CDCl₃, δ): 1.28 (2H, d, J=6 Hz), 1.70-1.86 (1H, m), 5.24 (4H, s),7.49 (4H, d, J=9 Hz), 8.25 (4H, d, J=9 Hz)

Preparation 9-7)

To a solution of(2S,4S)-2-(4-methylpiperazin-1-yl)-methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(6.85 g) in trifluoroacetic acid (35 ml) was added 2-mercaptoethanol(1.13 ml) under ice-cooling and the mixture was stirred at ambienttemperature for 15 minutes. The reaction mixture was concentrated invacuo. The resulting residue was dissolved in toluene (40 ml) and thesolution was evaporated in vacuo to give a syrup. The syrup wasdissolved in ethyl acetate (100 ml) and washed successively withsaturated aqueous sodium hydrogen carbonate and saturated aqueous sodiumchloride, dried over magnesium sulfate, and evaporated in vacuo to givea residue. The residue was chromatographed on silica gel (100 g) elutingwith a mixture of dichloromethane and acetone (10:1 V/V). The fractionscontaining the desired compound were collected and evaporated in vacuoto give(2S,4S)-4-mercapto-2-(4-methylpiperazin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(2.14 g).

NMR (CDCl₃, δ), 1.46-2.10 (2H, m), 2.28-2.66 (2H, m), 2.72 (3H, s),3.80-4.20 (2H, m), 5.16 (2H, s), 7.45 (2H, d, J=8 Hz), 8.13 (2H, d, J=8Hz)

Preparation 10

To a solution of(2S,4R)-2-aminomethyl-4-t-butyldimethylsilyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(5 g) and triethylamine (1.87 ml) in N,N-dimethylformamide (50 ml) wasdropwise added ethyl bromoacetate (1.49 ml) at ambient temperature withstirring. The mixture was stirred at 40° C. for 30 minutes and thenallowed to stand at ambient temperature for 6 hours. The reactionmixture was poured into saturated aqueous sodium chloride (100 ml) andextracted twice with ethyl acetate (100 ml). The extract was washed withsaturated aqueous sodium chloride, dried over magnesium sulfate andevaporated in vacuo. The resulting residue was subjected to a columnchromatography on silica gel (100 g) eluting with a mixture ofdichloromethane and acetone (20:1 V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4R)-4-t-butyldimethylsilyloxy-2-[(ethoxycarbonylmethyl)-aminomethyl]-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(3.52 g).

IR (Neat): 1740, 1710, 1610, 1530, 1350, 1260 cm⁻¹

NMR (CDCl₃, δ): 0.06 (6H, s), 0.83 (9H, s), 1.24 (3H, t, J=7 Hz),1.88-2.20 (2H, m), 5.24 (2H, s), 7.40-7.65 (2H, m), 8.23 (2H, d, J=8 Hz)

Preparation 11

To a solution of(2S,4R)-4-t-butyldimethylsilyloxy-2-[(ethoxycarbonylmethyl)aminomethyl]-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(6.55 g) in a mixture of tetrahydrofuran (80 ml) and water (40 ml) wereadded conc. hydrochloric acid (1.05 ml) and a solution of potassiumcyanate (1.61 g) in water (10 ml) and the mixture was stirred at 50°-60°C. for 1 hour. To a reaction mixture was added ethyl acetate (100 ml).The organic layer was separated, washed with saturated aqueous sodiumchloride, dried over anhydrous magnesium sulfate and evaporated invacuo. The resulting residue was chromatographed on silica gel (150 g)eluting with a mixture of dichloromethane and acetone (9:1 V/V). Thefractions containing the desired compound were collected and evaporatedin vacuo to give(2S,4R)-4-t-butyldimethylsilyloxy-2-(N-carbamoyl-N-ethoxycarbonylmethyl)-aminomethyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(5.24 g).

NMR (CDCl₃, δ): 0.06 (6H, s), 0.85 (9H, s), 1.23 (3H, t, J=7 Hz),1.70-2.30 (2H, m), 2.75-3.25 (1H, m), 3.30-3.60 (2H, m), 3.65-4.50 (6H,m), 5.25 (2H, s ), 5.52 (1H, broad s), 7.45 (2H, d, J=8 Hz), 8.25 (2H,d, J=8 Hz)

Preparation 12

A solution of(2S,4R)-4-t-butyldimethylsilyloxy-2-(N-carbamoyl-N-ethoxycarbonylmethyl)aminomethyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(5.22 g) in a mixture of aqueous 1N sodium hydroxide solution (15 ml)and tetrahydrofuran (50 ml) was stirred at 35°-40° C. for 30 minutes. Tothe reaction mixture was added ethyl acetate (50 ml) and the organiclayer was separated, washed with saturated aqueous sodium chloride,dried over magnesium sulfate, and evaporated in vacuo. The resultingresidue was chromatographed on silica gel (100 g) eluting with a mixtureof dichloromethane and acetone (9:1 V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4R)-4-t-butyldimethylsilyloxy-2-(2,4-dioxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(4.78 g).

IR (Nujol): 1765, 1735, 1675, 1610, 1525, 1350, 1140 cm⁻¹

NMR (CDCl₃, δ): 0.06 (6H, s), 0.84 (9H, s), 1.70-2.10 (2H, m), 3.28-4.50(8H, m), 5.22 (2H, s), 7.52 (2H, d, J=8 Hz), 8.24 (2H, d, J=8 Hz),8.35-8.70 (1H, m)

Preparation 13

A solution of(2S,4R)-4-t-butyldimethylsilyloxy-2-(2,4-dioxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(4.78 g) in a mixture of methanol (100 ml) and conc. hydrochloric acid(1.62 ml) was stirred at ambient temperature for 1 hour. The reactionmixture was evaporated in vacuo. The resulting residue was dissolved intoluene (30 ml) and the solution was concentrated under reduced pressureto give a residue. The residue was chromatographed on silica gel (60 g)eluting with a mixture of dichloromethane and acetone (2:1 V/V). Thefractions containing the desired compound were collected and evaporatedin vacuo to give(2S,4R)-2-(2,4-dioxoimidazolidin-1-yl)methyl-4-hydroxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(3.27 g).

IR (Nujol): 1720, 1530, 1090 cm⁻¹

NMR (CDCl₃, δ): 1.95-2.30 (2H, m), 5.26 (2H, s), 7.55 (2H, d, J=8 Hz),8.27 (2H, d, J=8 Hz)

EI Mass: 378 (M⁺)

Preparation 14

To a suspension of sodium borohydride (0.42 g) in tetrahydrofuran (20ml) was dropwise added boron trifluoride etherate (5.25 ml) underice-cooling and the mixture was stirred at the same temperature for 10minutes. To this solution was added a solution of(2S,4R)-2-(2,4-dioxoimidazolidin-1-yl)methyl-4-hydroxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(2.1 g) in tetrahydrofuran (10 ml) under ice-cooling and the mixture wasstirred at ambient temperature for 3 hours. To the reaction mixture wasdropwise added methanol (5 ml) and the mixture was filtered off. Thefiltrate was evaporated in vacuo. The resulting residue was dissolved inmethanol (30 ml) and 1.7M hydrogen chloride-methanol solution (6 ml) andthe solution was allowed to stand overnight at ambient temperature. Thereaction mixture was evaporated in vacuo and dissolved in ethyl acetate(60 ml). The solution was washed successively with saturated aqueoussodium hydrogen carbonate and saturated aqueous sodium chloride, driedover magnesium sulfate, and evaporated in vacuo to give precipitates.The precipitates were washed with ethyl acetate (20 ml) and air-dried togive(2S,4R)-4-hydroxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine (1.39 g).

IR (Nujol): 1695, 1660, 1605, 1525, 1500, 1350 cm⁻¹

NMR (DMSO-d₆, δ): 1.75-2.15 (2H, m), 3.00-3.60 (8H, m), 3.90-4.45 (2H,m), 4.96 (1H, d, J=3 Hz), 5.25 (2H, s), 6.31 (1H, s), 7.70 (2H, broad d,J=7 Hz), 8.29 (2H, d, J=8 Hz)

Preparation 15-1)

To a solution of(2S,4R)-4-hydroxy-1--(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(1.60 g), pyridine (0.43 ml) and N,N-dimethylaminopyridine (0.54 g) indichloromethane (20 ml) was added methanesulfonyl chloride (0.37 ml)under ice-cooling and the mixture was stirred under the same conditionfor 1 hour and then allowed to stand at ambient temperature for 3 hours.The reaction mixture was washed successively with 1N hydrochloric acid,aqueous sodium hydrogen carbonate and aqueous sodium chloride, driedover magnesium sulfate, and evaporated in vacuo. The resulting residuewas chromatographed on silica gel (100 g) eluting with a mixture ofchloroform and methanol (9:1 V/V). The fractions containing the desiredcompound were collected and evaporated in vacuo to give(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(1.90 g).

IR (Neat): 1720-1690, 1610, 1525, 1495, 1350, 1275 cm⁻¹

NMR (CDCl₃, δ) 1.75-2.06 (1H, m), 2.27-2.56 (2H, m), 3.03 (3H, s),3.16-4.47 (9H, m), 4.80-5.20 (1H, m), 5.30 (2H, s), 7.56 (2H, d, J=8Hz), 8.24 (2H, d, J=8 Hz)

Preparation 15-2)

(2S,4R)-2-(3-Methylsulfonyl-2-oxoimidazolidin-1-yl)-methyl-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 96.7% yield in substantially the same manner as that ofPreparation 15-1) except for using triethylamine in place of pyridine.

NMR (CDCl₃, δ): 2.00-2.60 (2H, m), 3.03 (3H, s) 3.26 (3H, s), 5.26 (2H,s), 7.56 (2H, broad d, J=8 Hz), 8.28 (2H, d, J=8 Hz)

Preparation 15-3)

(2S,4R)-2-(2,4-dioxoimidazolidin-1-yl)methyl-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 37.6% yield in substantially the same manner as that ofPreparation 15-1).

IR (Nujol): 1720-1690, 1610, 1530-1520 cm⁻¹

NMR (CDCl₃, δ): 2.10-2.70 (1H, m), 3.06 (3H, s), 3.35-4.50 (8H, m), 5.29(3H, broad s), 7.56 (2H, d, J=8 Hz), 8.10-8.30 (1H, m), 8.28 (2H, d, J=8Hz)

Preparation 16-1)

To a solution of(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)-methylpyrrolidine(1.84 g) in dimethylformamide (40 ml) was added potassium thioacetate(0.95 g) and the mixture was stirred at 70°-80° C. for 2 hours. Thereaction mixture was poured into ice-water (200 ml) and extracted 3times with ethyl acetate (100 ml). The extract was washed with saturatedaqueous sodium chloride, dried over anhydrous magnesium sulfate andevaporated in vacuo. The resulting residue was chromatographed on silicagel (100 g) eluting with a mixture of chloroform and methanol (9:1 V/V).The fractions containing the desired compound were collected andevaporated in vacuo to give(2S,4S)-4-acetylthio-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(1.23 g).

NMR (CDCl₃, δ): 1.50-1.80 (2H, m), 2.33 (3H, s), 5.25 (2H, s), 7.57 (2H,d, J=8 Hz), 8.28 (2H, d, J=8 Hz)

Preparation 16-2)

(2S,4S)-4-Acetylthio-2-(3-methylsulfonyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 56.9% yield in substantially the same manner as that ofPreparation 16-1).

IR (Nujol): 1730, 1710-1700, 1610, 1525, 1350 cm⁻¹

NMR (CDCl₃, δ): 1.65-2.05 (1H, m), 2.20 (3H, s), 3.27 (3H, s), 3.25-4.35(11H, m), 5.25 (2H, s), 7.56 (2H, d, J=8 Hz), 8.26 (2H, d, J=8 Hz)

Preparation 16-3)

(2S,4S)-4-Acetylthio-2-(2,4-dioxoimidazolidin-1-yl)-methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 87.4% yield in substantially the same manner as that ofPreparation 16-1).

IR (Nujol): 1765, 1720, 1690, 1650, 1610, 1525, 1350 cm⁻¹

NMR (CDCl₃, δ): 1.60-2.10 (1H, m), 5.20 (2H, s), 7.54 (2H, d, J=8 Hz),8.25 (2H, d, J=8 Hz)

Preparation 17-1)

To a solution of(2S,4S)-4-acetylthio-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(1.22 g) in methanol (20 ml) was added 28% sodium methoxide in methanolsolution (0.61 ml) on ice-bath under atmospheric pressure of nitrogenand the mixture was stirred at the same condition for 30 minutes. To areaction mixture was added acetic acid (0.17 ml) and evaporated invacuo. The resulting residue was dissolved in ethyl acetate (50 ml) andthe solution was washed twice with saturated aqueous sodium chloride,dried over magnesium sulfate, and evaporated in vacuo. The resultingresidue was chromatographed on silica gel (150 g) eluting with a mixtureof chloroform and methanol (9:1 V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4S)-4-mercapto-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(0.76 g).

IR (Neat): 1710-1690, 1610, 1525, 1500, 1350, 1280 cm⁻¹

NMR (CDCl₃, δ): 1.60-2.05 (2H, m), 2.33-3.10 (2H, m), 3.10-3.80 (7H, m),3.85-4.33 (2H, m), 4.85-5.16 (1H, m), 5.24 (2H, s), 7.56 (2H, d, J=8Hz), 8.26 (2H, d, J=8 Hz)

EI Mass: 347 (M⁺ -33)

Preparation 17-2)

(2S,4S)-4-Mercapto-2-(3-methylsulfonyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 66.4% yield in substantially the same manner as that ofPreparation 17-1).

IR (Neat): 1720-1690, 1610, 1530-1520 cm⁻¹

NMR (CDCl₃, δ): 2.35-2.75 (1H, m), 3.10-4.30 (13H, m), 5.24 (2H, s),7.56 (2H, d, J=8 Hz), 8.26 (2H, d, J=8 Hz)

Preparation 17-3)

(2S,4S)-2-(2,4-Dioxoimidazolidin-1-yl)methyl-4-mercapto-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 58.4% yield in substantially the same manner as that ofPreparation 17-1).

IR (Nujol): 1765, 1720-1680, 1605, 1520 cm⁻¹

NMR (CDCl₃, δ): 3.00-4.35 (8H, m), 5.52 (2H, s), 7.48 (2H, d, J=8 Hz),8.00-8.20 (1H, m), 8.23 (2H, d, J=8 Hz)

Preparation 18

To a mixture of N,N-dimethylformamide (0.6 ml) and tetrahydrofuran (1.2ml) was added dropwise phosphorus oxychloride (0.58 ml) at -5° C. andthe mixture was stirred at 5° C. for 5 minutes. To the mixture was addeda solution of(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)proline (2.0 g)in tetrahydrofuran (20 ml) under ice-cooling. The solution was stirredat the same temperature for 30 minutes. To a solution were addedethyleneurea (2.22 g) and conc. sulfuric acid (0.035 ml), and themixture was stirred at 45°-50° C. for 3 hours. Ethyl acetate (100 ml)and water (40 ml) was poured into the reaction mixture. The organiclayer was washed with saturated aqueous sodium chloride, dried overanhydrous magnesium sulfate, and evaporated in vacuo to give a residue.The residue was chromatographed on silica gel (100 g) eluting with amixture of chloroform and methanol (9:1, V/V). The fractions containingthe desired compound were collected and evaporated in vacuo to give(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)carbonylpyrrolidine(1.98 g).

IR (Neat): 1710-1680, 1605, 1520-1510 cm⁻¹

NMR (CDCl₃, δ): 2.06-2.46 (1H, m), 2.58-3.05 (1H, m), 3.05 (3H, s),3.26-4.25 (6H, m), 4.95-5.44 (3H, m), 5.46-5.90 (2H, m), 7.43 (2H, d,J=8 Hz), 7.50 (2H, d, J=8 Hz), 8.22 (4H, d, J=8 Hz)

Preparation 19

To a solution of sodium borohydride (0.32 g) in tetrahydrofuran (20 ml)was added dropwise boron trifluoride etherate (6.0 ml) under ice-coolingand the mixture was stirred at the same temperature for 10 minutes. Tothe mixture was added a solution of(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)carbonylpyrrolidine (2.0 g) in tetrahydrofuran(10 ml) and the mixture was stirred at ambient temperature for 3 hours.To a reaction mixture was added dropwise methanol (30 ml) underice-cooling and the solution was evaporated in vacuo. The resultingresidue was dissolved in methanol (30 ml) and conc. hydrochloric acid(0.5 ml) and stirred overnight at ambient temperature. The reactionmixture was evaporated in vacuo to give a residue. The residue wasdissolved in a mixture of ethyl acetate (60 ml) and tetrahydrofuran (30ml) and the solution was washed with saturated aqueous sodium hydrogencarbonate and saturated aqueous sodium chloride successively, dried overanhydrous magnesium sulfate and evaporated in vacuo to give a residue.The residue was chromatographed on silica gel (100 g) eluting with amixture of chloroform and methanol (19:1 V/V). The fractions containingthe desired compound were collected and evaporated in vacuo to give(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(0.81 g).

NMR (CDCl₃, δ): 2.16-2.47 (2H, m), 3.00 (3H, s), 3.10-3.73 (6H, m),3.80-4.40 (2H, m), 4.67-4.90 (1H, m), 5.10-5.30 (3H, broad s), 7.48 (2H,d, J=8 Hz), 8.18 (2H, d, J=8 Hz)

Preparation 20

To a solution of(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)-methylpyrrolidine(0.80 g) in N,N-dimethylformamide (10 ml) was added sodium hydroxide (78mg) under ice-cooling and the mixture was stirred at the sametemperature for 20 minutes. To a solution was added iodomethane (0.34ml) and the mixture was stirred at 30° C.-50° C. for 1 hour. Thereaction mixture was poured into ice-water (30 ml) and extracted twicewith ethyl acetate (30 ml). The extract was washed with saturatedaqueous sodium chloride, dried over anhydrous magnesium sulfate andevaporated in vacuo. The resulting residue was chromatographed on silicagel (100 g) eluting with a mixture of chloroform and methanol(19:1,V/V). The fractions containing the desired compound were collectedand evaporated in vacuo to give(2S,4R)-4-methanesulfonyloxy-2-(3-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(0.78 g).

NMR (CDCl₃, δ): 2.18-2.48 (2H, m), 2.74 (3H, s), 2.98 (3H, s), 5.27 (2H,s), 7.48 (2H, d, J=8 Hz), 8.18 (2H, d, J=8 Hz)

Preparation 21

(2S,4R)-4-Methanesulfonyloxy-2-(3-methyl-2-oxoimidazolidin-1-yl)carbonyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine(0.71 g) was obtained by reacting(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)carbonylpyrrolidine(1.96 g) with sodium hydride (62% in oil suspension) (0.18 g) andiodomethane (0.40 ml) in substantially the same manner as that ofPreparation 20.

Preparation 22

To a solution of(2S,4R)-4-methanesulfonyloxy-2-(3-methyl-2-oxoimidazolidin-1-yl)carbonyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(0.70 g) in tetrahydrofuran (3.5 ml) was added 1.0M solution ofborane-tetrahydrofuran complex in tetrahydrofuran (20.9 ml) and themixture was stirred at ambient temperature for 1 hour and at 35°-40° C.for 2.5 hours. Methanol (20 ml) was added dropwise to the reactionmixture on ice-bath and the mixture was evaporated in vacuo. Theresulting residue was dissolved in a mixture of methanol (20 ml) and1.7M solution of hydrogen chloride in methanol (1 ml) and the mixturewas allowed to stand overnight. The reaction mixture was evaporated invacuo to give a residue. The residue was dissolved in ethyl acetate (60ml) and the solution was washed with saturated aqueous sodium hydrogencarbonate and aqueous sodium chloride, dried over anhydrous magnesiumsulfate and evaporated in vacuo. The resulting residue waschromatographed on silica gel (30 g) eluting with a mixture ofchloroform and methanol (9:1, V/V). The fractions containing the desiredcompound were collected and evaporated in vacuo to give(2S,4R)-4-methanesulfonyloxy-2-(3-methyl-2-oxoimidazolidin-1-yl)-methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(0.33 g).

Preparation 23

To a solution of sodium hydride (0.35 g) in N,N-dimethylformamide (30ml) was added dropwise thioacetic S-acid (0.74 ml) with stirring underice-cooling. The mixture was stirred at the same temperature for 30minutes. A solution of(2S,4R)-4-methanesulfonyloxy-2-(3-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine(3.17 g) in N,N-dimethylformamide (7 ml) was added to the mixtureobtained above with stirring at the same temperature. The mixture wasstirred at 80°-90° C. for 2 hours. The reaction mixture was poured intoice-water (100 ml) and extracted twice with ethyl acetate (100 ml). Theextract was washed with saturated aqueous sodium chloride, dried overanhydrous magnesium sulfate and evaporated in vacuo. The resultingresidue was chromatographed on silica gel (100 g) eluting with a mixtureof chloroform and methanol (19:1, V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4S)-4-acetylthio-2-(3-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine (1.74 g).

IR (Neat): 1710-1670, 1610, 1520 cm⁻¹

NMR (CDCl₃, δ): 2.28 (3H, s), 2.77 (3H, s), 5.18 (2H, s), 7.46 (2H, d,J=8 Hz), 8.16 (2H, d, J=8 Hz)

Preparation 24

To a solution of(2S,4S)-4-acetylthio-2-(3-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine(1.72 g) in methanol (40 ml) was added 28% sodium methoxide in methanolsolution (0.83 ml) and the mixture was stirred under ice-cooling for 30minutes. Acetic acid (0.25 ml) was added to the reaction mixture at thesame temperature. The mixture was evaporated in vacuo to give a residue.The residue was dissolved in a mixture of ethyl acetate (80 ml) andtetrahydrofuran (30 ml) and the solution was washed with saturatedaqueous sodium chloride, dried over anhydrous magnesium sulfate andevaporated in vacuo. The resulting residue was chromatographed on silicagel (100 g) eluting with a mixture of chloroform and methanol (19:1,V/V). The fractions containing the desired compound were collected andevaporated in vacuo to give(2S,4S)-4-mercapto-2-(3-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(1.23 g).

IR (Neat): 1710-1670, 1605, 1525-1495 cm⁻¹

NMR (CDCl₃, δ): 1.64-1.97 (2H, m), 2.28-2.68 (1H, m), 1.74 (3H, s),3.03-3.70 (8H, m), 3.80-4.25 (2H, m), 5.16 (2H, s), 7.49 (2H, d, J=9Hz), 8.17 (2H, d, J=9 Hz)

Preparation 25

To a solution of(2S,4S)-2-(methanesulfonyloxy)-methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(8.76 g) in dimethylformamide (80 ml) were added(2S)-2-(hydroxymethyl)pyrrolidine (8.72 g) and triethylamine (3.86 ml)and the mixture was stirred at 100° C. for 5 hours. The reaction mixturewas poured into ice-water (300 ml) and extracted twice with ethylacetate (200 ml). The extract was washed with saturated aqueous sodiumchloride, dried over magnesium sulfate and evaporated in vacuo. Theresulting residue was chromatographed on silica gel (150 g) eluting witha mixture of dichloromethane and acetone (2:1, V/V). The fractionscontaining the desired compound were collected and evaporated in vacuoto give(2S,4S)-2-[(2S)-2-(hydroxymethyl)pyrrolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(5.75 g).

NMR (DCl₃, δ): 5.00-5.28 (2H, m), 7.05-7.65 (17H, m), 8.22 (2H, d, J=8Hz)

Preparation 26

To a solution of(2S,4S)-2-(methanesulfonyloxy)methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(7.1 g) in dimethylformamide (70 ml) was added sodium azide (1.09 g) andammonium chloride (0.90 g) and the mixture was stirred at 80°-90° C. for3 hours. The reaction mixture was poured into ice-water (200 ml) andextracted twice with ethyl acetate (200 ml). The extract was washed withsaturated aqueous sodium chloride, dried over magnesium sulfate andevaporated in vacuo. The resulting residue was chromatographed on silicagel (200 g) eluting with n-hexane and ethyl acetate (2:1, V/V). Thefractions containing the desired compound were collected and evaporatedin vacuo to give(2S,4S)-2-azidomethyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(5.20 g).

IR (Neat): 2120, 1710-1700, 1610, 1525 cm⁻¹

NMR (CDCl₃, δ): 3.58-3.93 (2H, m), 5.12 (2H, s), 7.06-7.60 (17H, m),8.25 (2H, d, J=8 Hz)

Preparation 27

A solution of(2S,4S)-2-azidomethyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(5.18 g) and triphenylphosphine (3.75 g) in pyridine (15 ml) was stirredat ambient temperature for 1 hour. To a reaction mixture was added conc.ammonia water (1.2 ml) with stirring at ambient temperature and themixture was allowed to stand overnight at the same temperature. Thesolution was evaporated in vacuo to give a residue. The residue waschromatographed on silica gel (100 g) eluting with a mixture ofchloroform and methanol (9:1, V/V). The fractions containing the desiredcompound were collected and evaporated in vacuo to give(2S,4S)-2-aminomethyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(6.13 g).

NMR (CDCl₃, δ): 3.50-3.83 (1H, m), 5.12 (2H, s), 8.25 (2H, d, J=8 Hz)

Preparation 28

To a solution of(2S,4S)-2-aminomethyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(7.78 g) in a mixture of tetrahydrofuran (120 ml) and water (40 ml) wasadded dropwise chloroacetyl chloride (1.23 ml) with stirring underice-cooling, keeping the pH 8-10 with triethylamine. The mixture wasstirred at the same temperature for 1 hour. The reaction mixture wasevaporated in vacuo to remove the organic layer. The resulting residuewas extracted twice with ethyl acetate (100 ml). The extract was washedwith saturated aqueous sodium chloride, dried over anhydrous magnesiumsulfate and evaporated in vacuo to give(2S,4S)-2-(chloroacetylamino)methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(7.35 g).

Preparation 29

A solution of(2S,4S)-2-(chloroacetylamino)-methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)-pyrrolidine(1.0 g), potassium cyanate (1.3 g) and tetra-n-butylammonium iodide (0.2g) in acetonitrile (50 ml) was stirred at 60°-80° C. for 8 hours. To areaction mixture was added ethyl acetate (150 ml) and the organic layerwas separated, washed with saturated aqueous sodium chloride, dried overanhydrous magnesium sulfate, and evaporated in vacuo. The resaltingresidue was chromatographed on silica gel (50 g) eluting with a mixtureof chloroform and acetone (9:1, V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4S)-2-(2,5-dioxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(0.82 g).

IR (Nujol): 1775, 1710-1700, 1600, 1520 cm⁻¹

NMR (CDCl₃, δ): 1.25-1.77 (1H, m), 1.90-2.40 (1H, m), 2.50-3.25 (3H, m),3.35-3.93 (4H, m), 3.94-4.33 (1H, m), 5.06 (2H, broad s), 5.43-5.80 (1H,m), 7.00-7.68 (17H, m), 8.18 (2H, d, J=8 Hz)

Preparation 30-1)

To a solution of(2S,4S)-2-[(2S)-2-(hydroxymethyl)-pyrrolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(5.74 g) in trifluoroacetic acid (30 ml) was added 2-mercaptoethanol(0.95 ml) under ice-cooling and the mixture was stirred at ambienttemperature for 15 minutes. The reaction mixture was evaporated invacuo. The resulting residue was dissolved in toluene (30 ml) and thesolution was evaporated in vacuo to give a residue. The residue wasdissolved in ethyl acetate (100 ml) and the solution was washed in turnwith saturated aqueous sodium hydrogen carbonate and aqueous sodiumchloride, dried over magnesium sulfate and evaporated in vacuo. Theresulting residue was chromatographed on silica gel (100 g) eluting witha mixture of chloroform and methanol (9:1, V/V). The fractionscontaining the desired compound were collected and evaporated in vacuoto give(2S,4S)-2-[(2S)-2-(hydroxymethyl)pyrrolidin-1-yl]methyl-4-mercapto-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(1.77 g).

IR (Nujol): 1710-1660, 1610, 1545 cm⁻¹

NMR (CDCl₃, δ): 1.68-2.35 (5H, m), 2.58-3.02 (2H, m), 3.27-4.37 (12H,m), 5.26 (2H, s), 7.55 (2H, d, J=9 Hz), 8.27 (4H, d, J=9 Hz)

Preparation 30-2)

(2S,4S)-2-(2,5-Dioxoimidazolidin-1-yl)methyl-4-mercapto-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 13.6% yield in substantially the same manner as that ofPreparation 30-1).

IR (Neat): 1760, 1710-1685, 1605, 1525 cm⁻¹

NMR (CDCl₃, δ): 3.05-3.46 (2H, m), 5.10-5.38 (2H, m), 5.70-6.00 (1H, m),7.40-7.70 (2H, m), 8.20 (2H, d, J=9 Hz)

FB Mass: 395 (M⁺ +1)

Preparation 31-1)

(2S,4S)-2-(3-Oxopiperazin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(3.50 g) was obtained by reacting(2S,4S)-2-(methanesulfonyloxy)methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(5.5 g) with 2-oxopiperazine (1.76 g) in substantially the same manneras that of Preparation 3-1).

IR (Neat): 1700, 1605, 1525, 1265 cm⁻¹

NMR (CDCl₃, δ): 5.07-5.33 (2H, m), 7.10-7.68 (17H, m), 8.28 (2H, d, J=8Hz)

Preparation 31-2)

(2S,4S)-2-(Morpholinomethyl)-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(2.49 g) was obtained by reacting(2S,4S)-2-(methanesulfonyloxy)-methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(5.0 g) with morpholine (2.07 ml) in substantially the same manner asthat of Preparation 3-1).

Preparation 32

A mixture of(2S,4S)-2-(methanesulfonyloxy)methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)-pyrrolidine(2.28 g) and piperazine (0.93 g) in dimethylformamide (40 ml) wasstirred at 80°-90° C. for 5 hours. The reaction mixture was poured intoice-water (150 ml). The precipitates were collected by filtration,washed with water and dissolved in ethyl acetate (100 ml). The solutionwas washed twice with saturated aqueous sodium chloride (30 ml), driedover anhydrous magnesium sulfate and evaporated in vacuo to give aresidue. The residue was dissolved in a mixture of tetrahydrofuran (20ml) and water (10 ml). To the solution were added conc. hydrochloricacid (0.60 ml) and potassium cyanate (0.44 g) and the mixture wasstirred at 50° C. for 30 minutes. Ethyl acetate was added to thereaction mixture with stirring. The organic layer was separated andwashed twice with saturated aqueous sodium chloride, dried overanhydrous magnesium sulfate, and evaporated in vacuo. The resultingresidue was chromatographed on silica gel (100 g) eluting with a mixtureof dichloromethane and acetone (2:1, V/V and then 1:2, V/V). Thefractions containing the desired compound were collected and evaporatedin vacuo to give(2S,4S)-2-(4-carbamoylpiperazin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-4-(triphenylmethylthio)pyrrolidine(1.30 g).

IR (Nujol): 1710-1700, 1690, 1670-1650, 1590, 1520 cm⁻¹

NMR (CDCl₃, δ): 4.40-4.58 (2H, m), 5.11 (2H, s), 7.15-7.65 (17H, m),8.25 (2H, d, J=8 Hz)

Preparation 33-1)

(2S,4S)-2-(3-Oxopiperazin-1-yl)methyl-4-mercapto-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 27.4% yield in substantially the same manner as that ofPreparation 30-1).

Preparation 33-2)

(2S,4S)-4-Mercapto-2-(morpholinomethyl)-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 66.4% yield in substantially the same manner as that ofPreparation 30-1).

mp: 93°-94° C.

NMR (CDCl₃, δ): 1.66-2.05 (2H, m), 2.30-2.85 (6H, m), 3.00-3.50 (2H, m),3.55-3.75 (4H, m), 3.83-4.26 (2H, m), 5.19 (2H, s), 7.52 (2H, d, J=8Hz), 8.25 (2H, d, J=8 Hz)

EI Mass: 381 (M⁺)

Preparation 33-3)

(2S,4S)-2-(4-Carbamoylpiperazin-1-yl)methyl-4-mercapto-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 42.9% yield in substantially the same manner as that ofPreparation 30-1).

NMR (CDCl₃, δ): 1.66-2.13 (2H, m), 2.33-2.86 (7H, m), 3.05-3.55 (6H, m),3.80-4.28 (2H, m), 4.55 (2H, broad s), 5.22 (2H, s), 7.53 (2H, d, J=8Hz), 8.25 (2H, d, J=8 Hz)

Preparation 34

A mixture of 2-(2-aminoethylamino)ethanol (25 g) and dimethyl carbonate(75 ml) was refluxed for 4 hours. The reaction mixture was evaporated invacuo to give a residue. The residue was chromatographed on silica gel(500 g) eluting with a mixture of chloroform, methanol and conc. ammoniawater (4:1:0.1, V/V). The fractions containing the desired compound werecollected and evaporated in vacuo to give a residue (24.03 g). To theresidue was added 1,8-diazabicyclo[5.4.0]undec-7-ene (2.23 ml) and themixture was stirred at 150° C. for 3 hours. The reaction mixture wascooled and chromatographed on silica gel (200 g) eluting with a mixtureof chloroform, methanol and conc. ammonia water (9:1:0.1, V/V). Thefractions containing the desired compound were collected and evaporatedin vacuo to give 3-(2-hydroxyethyl)-2-oxoimidazolidine (13.53 g).

NMR (CDCl₃, δ): 3.20-4.00 (9H, m),5.23-5.52 (1H, m)

Preparation 35

To a mixture of N,N-dimethylformamide (0.6 ml) and tetrahydrofuran (1.2ml) was added dropwise phosphorus oxychloride (0.58 ml) at -5° C. andthe mixture was stirred at 5° C. for 5 minutes. To the mixture was addeda solution of(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)proline (2.0 g)in tetrahydrofuran (20 ml) under ice-cooling. The solution was stirredat the same temperature for 30 minutes. To this solution were added3-(2-hydroxyethyl)-2-oxoimidazolidine (1.0 g) and conc. sulfuric acid(0.035 ml) and the mixture was stirred at 45°-50° C. for 2 hours. Ethylacetate (50 ml) and water (30 ml) was added to the reaction mixture. Theorganic layer was washed with saturated aqueous sodium chloride, driedover anhydrous magnesium sulfate and evaporated in vacuo to give aresidue. The residue was chromatographed on silica gel (50 g) elutingwith a mixture of chloroform and methanol (19:1, V/V). The fractionscontaining the desired compound were collected and evaporated in vacuoto give(2S,4R)-2-[3-(2-hydroxyethyl)-2-oxoimidazolidin-1-yl]carbonyl-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine(0.19 g).

IR (Neat): 1725-1670, 1605, 1530-1510 cm⁻¹

NMR (CDCl₃, δ): 1.50-1.90 (1H, m), 2.07-2.43 (2H, m), 2.61-3.00 (1H, m),3.05 (3H, s), 3.30-4.03 (10H, m), 5.07-5.47 (2H, m), 5.60-5.95 (1H, m),7.52 (1H, d, J=8 Hz), 8.18 (2H, d, J=8 Hz)

FB Mass: 501 (M⁺)

Preparation 36

To a suspension of sodium borohydride (0.71 g) in tetrahydrofuran (25ml) was added dropwise boron trifluoride etherate (11.8 ml) underice-cooling and stirred at the same temperature for 10 minutes. To themixture was added a solution of(2S,4R)-2-[3-(2-hydroxyethyl)-2-oxoimidazolidin-1-yl]carbonyl-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(4.73 g) in tetrahydrofuran (50 ml) and the mixture was stirred atambient temperature overnight. To the reaction mixture was addeddropwise methanol (60 ml) under ice-cooling and evaporated in vacuo. Theresulting residue was dissolved in methanol (30 ml) and conc.hydrochloric acid (1 ml) and stirred at ambient temperature for 3 hours.The reaction mixture was evaporated in vacuo to give a residue. Theresidue was dissolved in ethyl acetate (100 ml) and the solution waswashed with saturated aqueous sodium hydrogen carbonate and aqueoussodium chloride successively, dried over anhydrous magnesium sulfate andevaporated in vacuo. The resulting residue was chromatographed on silicagel (100 g) eluting with a mixture of chloroform and methanol (19:1,V/V). The fractions containing the desired compound were collected andevaporated in vacuo to give(2S,4R)-2-[3-(2-hydroxyethyl)-2-oxoimidazolidin-1-yl]methyl-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(2.70 g).

NMR (CDCl₃, δ): 2.06-2.50 (2H, m), 3.02 (3H, s), 3.10-4.46 (13H, m),5.03-5.35 (3H, br. s), 7.50 (2H, d, J=8 Hz), 8.12 (2H, d, J=8 Hz)

Preparation 37

To a solution of(2S,4R)-2-aminomethyl-4-(t-butyldimethylsilyloxy)-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine(15 g) in a mixture of tetrahydrofuran (100 ml) and water (50 ml) wasadded dropwise 2-chloropropionylchloride (4.27 ml) with stirring underice-cooling, keeping the pH 9-10 with 4N sodium hydroxide. The mixturewas stirred at the same temperature for 1 hour. The reaction mixture wasevaporated in vacuo to remove the organic layer. The resulting residuewas extracted twice with ethyl acetate (100 ml). The extract was washedwith saturated aqueous sodium chloride, dried over anhydrous magnesiumsulfate and evaporated in vacuo to give(2S,4R)-4-(t-butyldimethylsilyloxy)-2-(2-chloropropionyl)aminomethyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine(18.36 g).

Preparation 38

A solution of(2S,4R)-4-(t-butyldimethylsilyloxy)-2-(2-chloropropionyl)aminomethyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(18.4 g), potassium cyanate (14.9 g) and tetrabutylammonium iodide (13.6g) in N,N-dimethylformamide (180 ml) was stirred at 100°-110° C. for 3hours. The reaction mixture was poured into water (300 ml) and extractedtwice with ethyl acetate (200 ml). The extract was washed with saturatedaqueous sodium chloride, dried over anhydrous magnesium sulfate andevaporated in vacuo. The resulting residue was dissolved in a mixture ofmethanol (150 ml) and conc. hydrochloric acid (6.1 ml). The solution wasstirred at ambient temperature for 2 hours and evaporated in vacuo. Theresulting residue was chromatographed on silica gel (250 g) eluting witha mixture of chloroform and methanol (19:1, V/V). The fractionscontaining the desired compound were collected and evaporated in vacuoto give(2S,4R)-4-hydroxy-2-(4-methyl-2,5-dioxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(8.16 g).

NMR (CDCl₃, δ): 1.36 (3H, d, J=7 Hz), 1.73-2.30 (3H, m), 2.53-2.88 (1H,m), 3.30-4.20 (5H, m), 4.22-4.68 (2H, m), 5.06-5.45 (2H, m), 5.98-6.35(1H, m), 7.46 (1H, d, J=8 Hz), 7.59 (1H, d, J=8 Hz), 8.19 (4H, d, J=8Hz)

Preparation 39

To a suspension of sodium borohydride (1.81 g) in tetrahydrofuran (50ml) was dropwise added boron trifluoride etherate (23.4 ml) underice-cooling and the mixture was stirred at the same temperature for 15minutes. To this solution was added a solution of(2S,4R)-4-hydroxy-2-(4-methyl-2,5-dioxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(9.37 g) in tetrahydrofuran (50 ml) under ice-cooling and the mixturewas stirred at ambient temperature overnight. To the reaction mixturewas dropwise added methanol (30 ml) and the mixture was filtered. Thefiltrate was evaporated in vacuo. The resulting residue was dissolved inmethanol (100 ml) and conc. hydrochloric acid (5 ml) and the solutionwas allowed to stand at ambient temperature for 3 hours. The reactionmixture was evaporated in vacuo and dissolved in ethyl acetate (300 ml).The solution was washed successively with saturated aqueous sodiumhydrogen carbonate and aqueous sodium chloride, dried over magnesiumsulfate and evaporated in vacuo. The resulting residue waschromatographed on silica gel (150 g) eluting with a mixture ofchloroform and methanol (19:1, V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4R)-4-hydroxy-2-(4-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(4.31 g).

IR (Neat): 1705 (sh), 1690, 1605, 1525, 1495 cm⁻¹

NMR (CDCl₃, δ): 1.19 (3H, d, J=6 Hz), 1.90-2.20 (2H, m), 2.70-3.10 (1H,m), 3.13-3.90 (7H, m), 4.00-4.30 (1H, m), 4.33-4.60 (1H, m), 4.73-8.00(1H, m), 5.20 (2H, s), 7.50 (2H, d, J=8 Hz), 8.28 (2H, d, J=8 Hz)

Preparation 40

To a solution of(2S,4R)-4-hydroxy-2-(4-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine(4.30 g) in dichloromethane (50 ml) were added successively pyridine(1.1 ml), 4-(N,N-dimethylamino)pyridine (1.39 g) and methanesulfonylchloride (0.97 ml) under ice-cooling and the mixture was stirred atambient temperature for 3 hours. The reaction mixture was washedsuccessively with 1N hydrochloric acid, aqueous sodium hydrogencarbonate and aqueous sodium chloride, dried over magnesium sulfate andevaporated in vacuo. The resulting residue was chromatographed on silicagel (100 g) eluting with a mixture of chloroform and methanol (19:1,V/V). The fractions containing the desired compound were collected andevaporated in vacuo to give(2S,4R)-4-methanesulfonyloxy-2-(4-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(4.76 g).

IR (Neat): 1710-1680, 1610, 1525, 1495, 1270, 1175 cm⁻¹

NMR (CDCl₃, δ): 1.19 (3H, d, J=6 Hz), 2.20-2.46 (2H, m), 2.70-3.00 (1H,m), 3.03 (3H, s), 3.15-4.43 (7H, m), 5.06-5.50 (4H, br.s), 7.51 (2H, d,J=8 Hz), 8.17 (2H, d, J=8 Hz)

Preparation 41-1)

(2S,4S)-4-Acetylthio-2-[3-(2-hydroxyethyl)-2-oxoimidazolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 71.0% yield in substantially the same manner as that ofPreparation 23.

NMR (CDCl₃, δ): 1.55-2.18 (2H, m), 2.32 (3H, s), 2.32-4.30 (15H, m),5.20 (2H, s), 7.50 (2H, d, J=8 Hz), 8.18 (2H, d, J=8 Hz)

Preparation 41-2)

(2S,4S)-4-Acetylthio-2-(4-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 81.0% yield in substantially the same manner as that ofPreparation 23.

NMR (CDCl₃, δ): 1.17 (3H, d, J=6 Hz), 1.65-2.10 (2H, m), 2.30-2.66 (1H,m), 2.90-4.26 (8H, m), 4.58 (1H, br.s), 5.18 (2H, s), 7.48 (2H, d, J=8Hz), 8.18 (2H, d, J=8 Hz)

Preparation 42-1)

(2S,4S)-2-[3-(2-Hydroxyethyl)-2-oxoimidazolidin-1-yl]methyl-4-mercapto-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 89.1% yield in substantially the same manner as that ofPreparation 24.

IR (Neat): 1710-1650, 1605 cm⁻¹

NMR (CDCl₃, δ): 1.60-2.16 (3H, m), 2.26-2.76 (1H, m), 2.95-3.62 (8H, m),3.72 (2H, t, J=5 Hz), 3.88-4.25 (2H, m), 5.18 (2H, s), 7.49 (2H, d, J=8Hz), 8.18 (2H, d, J=8 Hz)

EI Mass: 425 (M⁺ +1), 424 (M⁺)

Preparation 42-2)

(2S,4S)-4-Mercapto-2-(4-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 92.8% yield in substantially the same manner as that ofPreparation 24.

IR (Neat): 1710, 1690, 1605, 1520, 1490, 1345, 1270 cm⁻¹

NMR (CDCl₃, δ): 1.20 (3H, d, J=6 Hz), 1.66-2.13 (2H, m), 2.31-2.72 (1H,m), 2.76-4.30 (9H, m), 5.20 (3H, br, s), 7.50 (2H, d, J=8 Hz), 8.18 (2H,d, J=8 Hz)

EI Mass: 394 (M⁺), 361 (M⁺ -33)

Preparation 43

To a solution of(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzylocycarbonyl)-2-(2-oxoimidazolidin-1-yl)-methylpyrrolidine(5.60 g) and 4-(N,N-dimethylamino)-pyridine (1.36 g) in dichloromethane(60 ml) was dropwise added acetyl chloride (1.48 ml) under ice-coolingand the mixture was stirred at the same temperature overnight. Thereaction mixture was washed successively with 1N hydrochloric acid,aqueous sodium hydrogen carbonate and aqueous sodium chloride, driedover magnesium sulfate and evaporated in vacuo. The resulting residuewas chromatographed on silica gel (100 g) eluting with a mixture ofchloroform and methanol (19:1, V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give(2S,4R)-2-(3-acetyl-2-oxoimidazolidin-1-yl)methyl-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(1.13 g).

NMR (CDCl₃, δ): 1.66-1.95 (1H, m), 2.13 (3H, s), 2.13-2.65 (2H, m), 3.00(3H, s), 3.20-4.46 (9H, m), 5.20 (2H, s), 7.46 (2H, d, J=8 Hz), 8.16(2H, d, J=8 Hz)

Preparation 44

To a suspension of sodium borohydride (0.16 g) in tetrahydrofuran (11ml) was dropwise added boron trifluoride etherate (2.83 ml) underice-cooling and the mixture was stirred at the same temperature for 15minutes. To this solution was added a solution of(2S,4R)-2-(3-acetyl-2-oxoimidazolidin-1-yl)methyl-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-pyrrolidine (1.12 g)in tetrahydrofuran (2.83 ml) under ice-cooling and the mixture wasstirred at ambient temperature overnight. To the reaction mixture wasadded dropwise methanol (30 ml) and the mixture was filtrated. Thefiltrate was evaporated in vacuo. The resulting residue was dissolved inmethanol (30 ml) and conc. hydrochloric acid (0.5 ml) and the solutionwas allowed to stand at ambient temperature overnight. The reactionmixture was evaporated in vacuo and dissolved in ethyl acetate (50 ml).The solution was washed successively with saturated aqueous sodiumhydrogen carbonate and aqueous sodium chloride, dried over magnesiumsulfate and evaporated in vacuo. The resulting residue waschromatographed on silica gel (100 g) eluting with a mixture ofchloroform and methanol (19:1, V/V). The fractions containing thedisired compound were collected and evaporated in vacuo to give(2S,4R)-2-(3-ethyl-2-oxoimidazolidin-1-yl)methyl-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(1.04 g).

NMR (CDCl₃, δ): 1.06 (3H, t, J=6 Hz), 2.20-2.55 (2H, m), 2.99 (3H, s),3.05-4.40 (11H, m), 5.05-5.40 (3H, m), 7.48 (2H, d, J=8 Hz), 8.18 (2H,d, J=8 Hz)

Preparation 45

(2S,4S)-4-Acetylthio-2-(3-ethyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 93.0% yield in substantially the same manner as that ofPreparation 23.

NMR (CDCl₃, δ): 1.08 (3H, t, J=7 Hz), 1.76-2.19 (2H, m), 2.30 (3H, s),2.30-2.70 (1H, m), 3.07-3.68 (8H, m), 3.70-4.28 (3H, m), 5.20 (2H, s),7.50 (2H, d, J=9 Hz), 8.18 (2H, d, J=9 Hz)

Preparation 46

(2S,4S)-2-(3-Ethyl-2-oxoimidazolidin-1-yl)methyl-4-mercapto-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 85.4% yield in substantially the same manner as that ofPreparation 24.

IR (Neat): 1710, 1790, 1610, 1525, 1495 cm⁻¹

Preparation 47

A mixture of(2S,4R)-4-methanesulfonyloxy-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)-carbonylpyrrolidine(30 g), 10% palladium on carbon (10 g), methanol (300 ml) andtetrahydrofuran (150 ml) was stirred for 5 hours under atmosphericpressure of hydrogen at ambient temperature. After the catalyst wasfiltered off, the filtrate was evaporated in vacuo to give a residue.The residue was chromatographed on silica gel (250 g) eluting with amixture of chloroform and methanol (9:1 V/V). The fractions containingthe desired compound were collected and evaporated in vacuo to give(2S,4R)-4-methanesulfonyloxy-2-(2-oxoimidazolidin-1-yl)-carbonylpyrrolidine(14.92 g).

mp: 115°-118° C.

IR (Nujol): 1740, 1725, 1660, 1380 cm⁻¹

NMR (CDCl₃, δ): 2.23-2.37 (1H, m), 2.47-2.59 (1H, m), 2.80 (1H, br s),3.05 (3H, s), 3.28-3.31 (2H, m), 3.47-3.58 (3H, m), 3.85-4.02 (2H, m),4.96-5.05 (1H, m), 5.21-5.29 (1H, m), 6.07 (1H, s)

FD Mass: 277 (M⁺)

Preparation 48

To a solution of(2S,4R)-4-methanesulfonyloxy-2-(2-oxoimidazolidin-1-yl)carbonylpyrrolidine(14.9 g) in a mixture of methanol (150 ml) and tetrahydrofuran (150 ml)were added triethylamine (32.5 ml) and methyl iodide (11.4 ml) and themixture was stirred at 40° C. for 2 hours. The reaction mixture wasevaporated in vacuo. The resulting residue was chromatographed on silicagel (600 g) eluting with a mixture of chloroform and methanol (9:1 V/V).The fractions containing the desired compound were collected andevaporated in vacuo to give a residue. The residue was washed withdichloromethane (100 ml). The resulting precipitates were collected anddried in vacuo to give(2S,4R)-4-methanesulfonyloxy-1-methyl-2-(2-oxoimidazolidin-1-yl)carbonylpyrrolidine(2.30 g).

NMR (CDCl₃, δ): 2.09-2.36 (1H, m), 2.43 (3H, s), 2.55-2.79 (2H, m), 3.03(3H, s), 3.49-3.64 (3H, m), 3.93-4.02 (2H, m), 4.60 (1H, t, J=7.5 Hz),5.18-5.30 (1H, m), 5.65 (1H, br s)

Preparation 49

To a solution of sodium borohydride (0.60 g) in tetrahydrofuran (25 ml)was added dropwise boron trifluoride ether complex (5.8 ml) underice-cooling and the mixture was stirred at the same temperature for 15minutes. To the mixture was added a solution of(2S,4R)-4-methanesulfonyloxy-1-methyl-2-(2-oxoimidazolidin-1-yl)-carbonylpyrrolidine(2.3 g) in tetrahydrofuran (15 ml) and the mixture was stirred at thesame temperature for 5 hours. To the reaction mixture was added dropwisemethanol (15 ml) under ice-cooling. The mixture was filtered off and thefiltrate was evaporated in vacuo. The resulting residue was dissolved ina mixture of methanol (50 ml) and conc. hydrochloric acid (2 ml) and thesolution was stirred at ambient temperature overnight. The reactionmixture was evaporated in vacuo to give a residue. The residue wasdissolved in ethyl acetate (50 ml) and the solution was washed withsaturated aqueous sodium hydrogen carbonate and aqueous sodium chloridesuccessively, dried over anhydrous magnesium sulfate and evaporated invacuo. The resulting residue was chromatographed on silica gel (100 g)eluting with a mixture of chloroform and methanol (9:1 V/V). Thefractions containing the desired compound were collected and evaporatedin vacuo to give(2S,4R)-4-methanesulfonyloxy-1-methyl-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(1.89 g).

NMR (CDCl₃, δ): 2.09-2.17 (2H, m), 2.40 (3H, s), 2.48-2.56 (1H, m),2.62-2.74 (1H, m), 3.00 (3H, s), 2.97-3.08 (1H, m), 3.38-3.70 (6H, m),4.73 (1H, br s), 5.03-5.15 (1H, m)

Preparation 50

A solution of(2S,4R)-4-methanesulfonyloxy-1-methyl-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(2.50 g) and tetra-n-butylammonium thioacetate (4.16 g) in acetonitrile(70 ml) was stirred at 50°-60° C. for 4 hours. The reaction mixture wasevaporated in vacuo to give a residue. The residue was chromatographedon silica gel (200 g) eluting with a mixture of chloroform and methanol(20:1 V/V). The fractions containing the desired compound were collectedand evaporated in vacuo to give(2S,4S)-4-acetylthio-1-methyl-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(1.84 g).

IR (Neat): 1690-1680, 1495, 1270 cm⁻¹

NMR (CDCl₃, δ): 2.29 (3H, s), 2.35 (3H, s), 3.82-3.91 (1H, m), 4.61 (1H,br s)

Preparation 51

To a solution of(2S,4S)-4-acetylthio-1-methyl-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(1.83 g) in methanol (20 ml) was added 28% sodium methoxide in methanolsolution (1.50 ml) at -10°˜-5° C. and the mixture was stirred at thesame temperature for 30 minutes. To the reaction mixture was addedacetic acid (0.45 ml) at the same temperature and the mixture wasevaporated in vacuo. The resulting residue was chromatographed on silicagel (100 g) eluting with a mixture of chloroform and methanol (9:1 V/V).The fractions containing the desired compound were collected andevaporated in vacuo to give(2S,4S)-4-mercapto-1-methyl-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(0.60 g).

NMR (CDCl₃, δ): 1.67-1.79 (2H, m), 2.38 (3H, s), 2.39-2.58 (3H, m), 2.69(1H, dd, J=10 Hz, J=7 Hz), 2.97-3.10 (2H, m), 3.20-3.59 (6H, m),3.66-3.86 (1H, m)

EXAMPLE 1 ##STR11##

(PNB: 4-nitrobenzyl, PNZ: 4-nitrobenzyloxycarbonyl)

To a solution of 4-nitrobenzyl(4R)-2-diazo-4-[(2R,3S)-3-{(1R)-1-hydroxyethyl}-4-oxoazetidin-2-yl]-3-oxopentanoate(0.80 g) in 1,2-dichloroethane (16 ml) was added rhodium(II) acetate (2mg) under refluxing. After refluxing for 30 minutes, the reactionmixture was cooled and evaporated in vacuo to give a residue. Theresidue was dissolved in anhydrous acetonitrile (10 ml) and thenevaporated. This operation was repeated once again and the residue wasdried in vacuo to give 4-nitrobenzyl(4R,5R,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-carboxylate.The residue containing the compound obtained above was dissolved inanhydrous acetonitrile (16 ml) and cooled to 0° C. under an atmosphereof nitrogen. To this solution were added diphenyl phosphorochloridate(0.45 ml) and N,N-diisopropyl-N-ethylamine (0.46 ml) successively, andthe solution was stirred at 0° C. for 40 minutes.

To the resulting solution were added dropwise a solution of(2S,4S)-4-mercapto-1-(4-nitrobenzyloxycarbonyl)-2-[4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl]methylpyrrolidine(1.50 g) in acetonitrile (4 ml) and N,N-diisopropyl-N-ethylamine (0.46ml) with stirring at 5° C., and the stirring was continued at the sametemperature for 2 hours. To the reaction mixture was added ethyl acetate(30 ml) and water (10 ml) with stirring, and the organic layer wasseparated. This layer was washed with saturated aqueous sodium chloridesolution (30 ml×3), dried over magnesium sulfate and evaporated. Theresidue was chromatographed on silica gel (80 g) eluting with a mixtureof dichloromethane and acetone (2:1 v/v). The fractions containing thedesired compound were collected and evaporated in vacuo to give4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-{4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl}methylpyrrolidin-4-yl]thio-7-oxo-1-azabicyclo-[3.2.0]hept-2-ene-2-carboxylate(1.20 g).

IR (Nujol): 1765, 1705-1685, 1605, 1520, 1345, 1240 cm⁻¹

NMR (CDCl₃, δ): 1.26 (3H, d, J=6 Hz), 1.32 (3H, d, J=7 Hz), 5.06-5.62(6H, m), 7.49 (4H, d, J=8 Hz), 7.63 (2H, d, J=9 Hz), 8.28 (6H, d, J=8Hz)

EXAMPLE 2 ##STR12##

A mixture of 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-{4-(4-nitrobenzyloxycarbonyl)piperazin-1-yl}methylpyrrolidin-4-yl]thio-7-oxo-1-azabicyclo-[3.2.0]hept-2-ene-2-carboxylate(1.20 g), 20% palladium hydroxide on carbon (0.6 g), 0.2 M sodiumacetate-acetic acid buffer (pH=5.8, 50 ml) and tetrahydrofuran (50 ml)was stirred for 5 hours under atmospheric pressure of hydrogen atambient temperature. After the catalyst was filtered off, the filtratewas evaporated under reduced pressure to remove the organic solvent. Theresidue was chromatographed on nonionic adsorption resin, "Diaion HP-20"(trademark, made by Mitsubishi Chemical Industries) (30 ml) eluting inturn with water (80 ml) and 5% aqueous acetone (90 ml). The fractionscontaining the desired compound were collected and lyophilized to give(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-3-[(2S,4S)-2-(piperazin-1-yl)methylpyrrolidin-4-yl]thio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid (0.23 g).

mp: >181° C. (dec.)

IR (Nujol): 1755-1735, 1580-1540 cm⁻¹

NMR (D₂ O, δ): 1.23 (3H, d, J=8 Hz), 1.29 (3H, d, J=6 Hz), 1.50-1.90(2H,m), 2.50-3.06 (6H, m), 3.10-4.40 (12H, m)

SI Mass: 411 (M⁺)

The following compounds were obtained in substantially the same manneras that of Example 1.

EXAMPLE 3 ##STR13##

4-Nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate

IR (Nujol): 1770, 1690, 1605, 1520, 1350, 1275 cm⁻¹

NMR (CDCl₃, δ): 1.30 (3H, d, J=6 Hz), 1.33 (3H, d, J=6 Hz), 3.06-4.93(14H, m), 5.12-5.73 (4H, m), 7.60 (2H, d, J=8 Hz), 7.67 (2H, d, J=8 Hz),8.26 (4H, d, J=8 Hz)

EXAMPLE 4 ##STR14##

5-Nitrobenzyl(4R,5S,6S)-3-[(2S,4S)-2-{(2S)-2-carbamoylpyrrolidin-1-yl}methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]thio-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate

IR (Nujol): 1770-1760, 1710-1670, 1520 cm⁻¹

NMR (CDCl₃, δ): 1.29 (3H, d, J=7 Hz), 1.36 (3H, d, J=6 Hz), 1.70-2.10(4H, m), 5.10-5.70 (4H, m), 7.60 (2H, d, J=9 Hz), 7.69 (2H, d, J=9 Hz),8.27 (4H, d, J=9 Hz)

The following compounds were obtained in substantially the same manneras that of Example 2.

EXAMPLE 5 ##STR15##

(4R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-4-methyl-7-oxo-3-[(2S,4S)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid

mp: >184° C. (dec.)

IR (Nujol): 1760, 1690-1680, 1590, 1280 cm⁻¹

NMR (D₂ O, δ): 1.21 (3H, d, J=7 Hz), 1.28 (3H, d, J=6 Hz), 1.50-2.15(2H, m), 2.50-2.93 (1H, m), 3.20-4.35 (13H, m)

SI Mass: 411 (M⁺ +1)

EXAMPLE 6 ##STR16##

(4R,5S,6S)-3-[(2S,4S)-2-{(2S)-2-Carbamoylpyrrolidin-1-yl}methylpyrrolidin-4-yl]thio-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid

IR (Nujol): 1755-1740, 1665-1650, 1590-1580 cm⁻¹

NMR (D₂ O, δ): 1.17 (3H, d, J=7 Hz), 1.25 (3H, d, J=6 Hz), 1.50-2.05(4H, m), 4.10-4.40 (2H, m)

SI Mass: 439 (M⁺)

EXAMPLE 7 ##STR17##

4-Nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-{(3S)-3-(4-nitrobenzyloxycarbonylamino)pyrrolidin-1-yl]}methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2-carboxylatewas obtained in 57.5% yield in substantially the same manner as that ofExample 1.

IR (Nujol): 1760, 1710-1700, 1605, 1520, 1345 cm⁻¹

NMR (CDCl₃, δ): 1.31 (3H, d, J=7 Hz), 1.40 (3H, d, J=7 Hz), 5.05-5.60(6H, m), 7.58 (4H, d, J=9 Hz), 7.70 (2H, d, J=9 Hz), 8.28 (6H, d, J=9Hz)

EXAMPLE 8 ##STR18##

4-Nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(pyrrolidin-1-yl)methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 33.5% yield in substantially the same manner as that ofExample 1.

IR (Neat): 1770, 1705, 1610, 1525, 1350 cm⁻¹

NMR (CDCl₃, δ): 1.26 (3H, d, J=7 Hz), 1.36 (3H, d, J=7 Hz), 1.55-1.85(4H, m), 3.05-3.75 (4H, m), 3.86-4.38 (4H, m), 5.10-5.53 (4H, m), 7.54(2H, d, J=9 Hz), 7.67 (2H, d, J=9 Hz), 8.26 (4H, d, J=8 Hz)

EXAMPLE 9 ##STR19##

4-Nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-{4-(4-nitrobenzyloxycarbonylamino)piperidin-1-yl}methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]-thio-4-thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 55.3% yield in substantially the same manner as that ofExample 1.

IR (Nujol): 1765, 1710-1690, 1610 cm⁻¹

NMR (CDCl₃, δ): 1.25 (3H, d, J=6 Hz), 1.33 (3H, d, J=6 Hz), 5.03-5.49(4H, m), 7.50 (2H, d, J=8 Hz), 7.66 (2H, d, J=9 Hz), 8.22 (4H, d, J=9Hz)

EXAMPLE 10 ##STR20##

4-Nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-{3-methyl-4-(4-nitrobenzyloxycarbonyl)-piperazin-1-yl}methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2-carboxylatewas obtained in 64.6% yield in substantially the same manner to that ofExample 1.

IR (Nujol): 1765, 1710, 1790, 1605, 1515 cm⁻¹

NMR (CDCl₃, δ): 1.30 (6H, m), 1.37 (3H, d, J=6 Hz), 5.10-5.65 (4H, m),7.55 (2H, d, J=8 Hz), 7.70 (2H, d, J=8 Hz), 8.28 (4H, d, J=8 Hz)

EXAMPLE 11 ##STR21##

To a solution of 4-nitrobenzyl(4R)-2-diazo-4-[(2R,3S)-3-{(1R)-1-hydroxyethyl}-4-oxoazetidin-2-yl]-3-oxopentanoate(1.50 g) in 1,2-dichloroethane (30 ml) was added rhodium(II) acetate (5mg) under refluxing. After refluxing for 30 minutes, the reactionmixture was cooled and evaporated in vacuo to give a residue. Theresidue was dissolved in anhydrous acetonitrile (10 ml) and thenevaporated. This operation was repeated once again and the residue wasdried in vacuo to give 4-nitrobenzyl(4R,5R,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-carboxylate.The compound obtained was dissolved in anhydrous acetonitrile (30 ml)and cooled to 0° C. under an atmosphere of nitrogen. To this solutionwere added diphenyl phosphorochloridate (0.84 ml) andN,N-diisopropyl-N-ethylamine (0.74 ml) successively and the solution wasstirred at 0° C. for 40 minutes. To the resulting solution were addeddropwise a solution of(2S,4S)-4-mercapto-2-(4-methylpiperazin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine(1.97 g) in acetonitrile (10 ml) and N,N-diisopropyl-N-ethylamine (0.87ml) with stirring at 5° C., and the stirring was continued at the sametemperature for 2 hours. To the reaction mixture was added ethyl acetate(50 ml) and water (20 ml) with stirring, and the organic layer wasseparated. This layer was washed with saturated aqueous sodium chloridesolution (40 ml×3), dried over magnesium sulfate and evaporated. Theresidue was chromatographed on silica gel (100 g) eluting with a mixtureof chloroform and methanol (9:1 V/V). The fractions containing thedesired compound were collected and evaporated in vacuo to give4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-(4-methylpiperazin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(2.38 g).

IR (Nujol): 1760-1750, 1690, 1525 cm⁻¹

NMR (CDCl₃, δ): 1.26 (3H, d, J=6 Hz), 1.33 (3H, d, J=6 Hz), 1.80-2.18(2H, m), 2.27 (3H, s), 5.10-5.63 (4H, m), 7.48 (2H, d, J=8 Hz), 7.62(2H, d, J=8 Hz), 8.16 (4H, d, J=8 Hz)

EXAMPLE 12 ##STR22##

4-Nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-(3-methylsulfonyl-2-oxoimidazolidin-1-yl)-methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 49.5% yield in substantially the same manner as that ofExample 1.

IR (Nujol): 1765, 1710-1700, 1605, 1520, 1350 cm⁻¹

NMR (CDCl₃, δ): 1.27 (3H, d, J=8 Hz), 1.36 (3H, d, J=6 Hz), 1.60-2.05(3H, m), 2.36-2.86 (1H, m), 3.20-4.40 (18H, m), 5.12-5.67 (4H, m), 7.56(2H, d, J=9 Hz), 7.69 (2H, d, J=9 Hz), 8.26 (4H, d, J=9 Hz)

EXAMPLE 13 ##STR23##

4-Nitrobenzyl(4R,5S,6S)-3-[(2S,4S)-2-(2,4-dioxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidin-4-yl]thio-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 50% yield in substantially the same manner as that ofExample 1.

NMR (CDCl₃ +DMSO-d₆, δ): 1.28 (3H, d, J=7 Hz), 1.32 (3H, d, J=7 Hz),3.15-4.45 (11H, m), 5.15-5.65 (4H, m), 7.58 (2H, d, J=8 Hz), 7.68 (2H,d, J=8 Hz), 8.26 (4H, d)

EXAMPLE 14 ##STR24##

(4R,5S,6S)-3-[(2S,4S)-2-{(3S)-3-Aminopyrrolidin-1-yl}methylpyrrolidin-4-yl]thio-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid was obtained in 54.1% yield by catalytic reduction in substantiallythe same manner as that of Example 2.

mp: >187° C. (dec.)

IR (Nujol): 1755-1740, 1580-1560 cm⁻¹

NMR (D₂ O, δ): 1.20 (3H, d, J=7 Hz), 1.27 (3H, d, J=6 Hz), 1.46-2.06(2H, m), 2.27-4.35 (17H, m)

SI Mass: 411 (M⁺)

EXAMPLE 15 ##STR25##

(4R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-3-[(2S,4S)-2-(pyrrolidin-1-yl)methylpyrrolidin4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acidwas obtained in 59.7% yield by catalytic reduction in substantially thesame manner as that of Example 2.

mp: >193° C. (dec.)

IR (Nujol): 1750, 1590, 1150 cm⁻¹

NMR (D₂ O, δ): 1.20 (3H, d, J=8 Hz), 1.27 (3H, d, J=8 Hz), 1.83-2.26(4H, m), 2.42-3.10 (3H, m)

SI Mass: 396 (M⁺)

EXAMPLE 16 ##STR26##

(4R,5S,6S)-3-[(2S,4S)-2-{4-Aminopiperidin-1-yl}-methylpyrrolidin-4-yl]thio-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid was obtained in 26.7% yield by catalytic reduction in substantiallythe same manner as that of Example 2.

mp: >195° C. (dec.)

IR (Nujol): 1755-1740, 1590-1560 cm⁻¹

NMR (D₂ O, δ): 1.21 (3H, d, J=7 Hz), 1.27 (3H, d, J=7 Hz), 1.46-1.86(2H, m), 1.92-2.43 (4H, m)

SIMS: 425 (M⁺)

EXAMPLE 17 ##STR27##

(4R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-3-[(2S,4S)-2-{3-methylpiperazin-1-yl}methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid was obtained in 28.9% yield by catalytic reduction in substantiallythe same manner as that of Example 2.

mp: >196° C. (dec.)

IR (Nujol): 1755, 1585-1560 cm⁻¹

NMR (D₂ O, δ): 1.18 (3H, d, J=8 Hz), 1.25 (6H, d, J=8 Hz), 4.13-4.35(2H, m)

SI Mass: 425 (M⁺)

EXAMPLE 18 ##STR28##

A mixture of 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-(4-methylpiperazin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(1.40 g), 20% palladium hydroxide on carbon (0.7 g), 0.2M sodiumacetate-acetic acid buffer (pH=5.8, 50 ml) and tetrahydrofuran (50 ml)was stirred for 5 hours under atmospheric pressure of hydrogen atambient temperature. After the catalyst was filtered off, the filtratewas evaporated in vacuo to remove the organic solvent. The aqueous layerwas washed twice with ethyl acetate (20 ml) and evaporated in vacuo toremove the organic solvent. The residue was chromatographed on nonionicadosorption resin, "Diaion HP-20" (trademark, made by MitsubishiChemical Industries) (50 ml) eluting in turn with water (100 ml) and 10%aqueous acetone (200 ml). The fractions containing the desired compoundwere collected and hydrophilized to give(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-(4-methylpiperazin-1-yl)-methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo-[3.2.0]hept-2-ene-2-carboxylicacid (0.40 g).

mp: >145° C. (dec.)

IR (Nujol): 1760-1735, 1600-1580 cm⁻¹

NMR (D₂ O, δ): 1.23 (3H, d, J=8 Hz), 1.28 (3H, d, J=8 Hz), 1.45-1.85(1H, m), 2.30-2.66 (3H, m), 2.88 (3H, s)

FB Mass: 425 (M⁺)

EXAMPLE 19 ##STR29##

(4R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-3-[(2S,4S)-2-(3-methylsulfonyl-2-oxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid was obtained in 67.8% yield by catalytic reduction in substantiallythe same manner as that of Example 2.

mp: >183° C. (dec.)

IR (Nujol): 1755, 1720, 1680, 1350, 1165 cm⁻¹

NMR (D₂ O, δ): 1.21 (3H, d, J=7 Hz), 1.28 (3H, d, J=6 Hz), 1.50-2.00(1H, m), 2.55-3.00 (1H, m), 3.31 (3H, s), 3.36-4.33 (14H, m)

SI Mass: 489 (M⁺), 488 (M⁺ -1), 487 (M⁺ -2)

EXAMPLE 20 ##STR30##

(4R,5S,6S)-3-[(2S,4S)-2-(2,4-Dioxoimidazolidin-1-yl)-methylpyrrolidin-4-yl]thio-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid was obtained in 56.9% yield by catalytic reduction in substantiallythe same manner as that of Example 2.

mp: >191° C. (dec.)

IR (Nujol): 1760-1750, 1720, 1590-1580 cm⁻¹

NMR (D₂ O, δ): 1.22 (3H, d, J=9 Hz), 1.29 (3H, d, J=9 Hz), 1.45-2.00(2H, m), 2.50-3.05 (1H, m), 3.20-4.45 (11H, m)

Mass: 425 (M⁺ +1)

EXAMPLE 21 ##STR31##

To a solution of 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(pyrrolidin-1-yl)methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(0.35 g) in acetone (3.5 ml) was added methyl iodide (0.15 ml) atambient temperature. The mixture was stirred for hours. The reactionmixture was evaporated in vacuo to give 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-(1-methyl-1-pyrrolidinio)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylateiodide (0.35 g).

EXAMPLE 22 ##STR32##

(4R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-3-[(2S,4S)-2-(1-methyl-1-pyrrolidinio)methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 78.1% yield by catalytic reduction in substantially thesame manner as that of Example 2.

mp: >178° C. (dec.)

IR (Nujol): 1750, 1590, 1140 cm⁻¹

NMR (D₂ O, δ): 1.20 (3H, d, J=8 Hz), 1.28 (3H, d, J=6 Hz), 1.40-1.90(1H, m), 2.00-2.40 (4H, m), 2.56-3.00 (2H, m), 3.12 (3H, s)

SI Mass: 410 (M⁺)

EXAMPLE 23 ##STR33##

Allyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-7oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 38.0% yield in substantially the same manner as that ofExample 1.

This compound was immediately used as the starting compound of Example46.

The compounds listed in Table 1 were obtained in substantially the samemanner as that of Example 1.

                                      TABLE 1                                     __________________________________________________________________________     ##STR34##                                                                    Example                                                                       No.  R.sup.a  R.sup.b                                                                           R.sup.3                                                                          R.sup.c      data                                        __________________________________________________________________________    24   COOPNB   H   CH.sub.3                                                                          ##STR35##   IR(Neat): 1765, 1710-1690, 1620, 1580,                                        1525 cm.sup.-1 NMR(CDCl.sub.3,                                                δ): 1.27(3H, d, J=7Hz), 1.35(3H,                                        d, J=7Hz), 7.52(2H, d, J=8Hz), 7.67(2H,                                       d, J=8Hz), 8.25(4H, d, J=8Hz)               25   "        "   "                                                                                 ##STR36##   IR(Neat): 1775-1765, 1700, 1605, 1525                                         cm.sup.1                                    26   "        "   "                                                                                 ##STR37##   IR(Nujol): 1765, 1700, 1605, 1520, 1350                                       cm.sup.-1 NMR(CDCl.sub.3, δ):                                           1.28(3H, d, J=7Hz), 1.36(3H, d, J=7Hz),                                       .52-2.05(2H, m), 2.25-2.83(7H, m),                                            3.18-3.50(3H, m), 3.53- 3.86(5H, m),                                          3.90-4.45(4H, m), 5.12-5.68(4H, m),                                           7.57(2H, d, J=8Hz), 7.58(2H, d, J=8Hz),                                       8.26(4H, d, J=8Hz)                          27   "        "   "                                                                                 ##STR38##   IR(Nujol): 1765, 1710-1685, 1610, 1520                                        cm.sup.-1 NMR(CDCl.sub.3, δ):                                           1.30(3H, d, J=6Hz), 1.38(3H, d, J=6Hz),                                       .20-5.52(4H, m), 7.56(2H, d, J=9Hz),                                          7.69(2H, d, J=9Hz), 8.28(4H, d, J=9Hz)      28   COOPNB   H   CH.sub.3                                                                          ##STR39##   IR(Nujol): 1760, 1710-1670, 1600, 1520                                        cm.sup.-1 NMR(CDCl.sub.3, δ):                                           1.28(3H, d, J=7Hz), 1.36(3H, d, J=7Hz),                                       .80-2.15(1H, m), 2.30-2.70(1H, m),                                            2.77(3H, s), 3.10-3.75(10H,  m),                                              3.90-4.36(4H, m), 5.12-5.60(4H, m),                                           7.52(2H, d, J=9Hz), 7.62(2H, d,                                               J=9Hz)8.20(4H, d, J=9Hz)                    29                                                                                  ##STR40##                                                                             "   "                                                                                 ##STR41##   IR(Nujol): 1770-1750, 1710-1690, 1605,                                        1525 cm.sup.-1 NMR(CDCl.sub.3,                                                δ): 1.25(3H, d, J=7Hz), 1.33(3H,                                        d, J=7Hz), 2.38-2.80(1H, m),                                                  5.45-5.73(1H, m), 5.80-6.23(1H, m),                                           7.50-7.65(2H, m), 8.18(2H, d, J=8Hz)        30   COOPNB   PNZ H                                                                                 ##STR42##   IR(Nujol): 1780-1770, 1710, 1790, 1605,                                       1515 cm.sup.-1                              __________________________________________________________________________

The following compound was obtained in substantially the same manner asthat of Example 1.

EXAMPLE 31 ##STR43##

IR (neat): 1770-1760, 1710-1680, 1610, 1525 cm⁻¹

NMR(CDCl₃, δ): 1.26 (3H, d, J=6 Hz, 1.33 (3H, d, J=7 Hz), 1.72-2.08 (2H,m), 2.28-2.75 (2H, m), 3.07-4.43 (18H, m), 5.06-5.60 (4H, m), 7.49 (2H,d, J=8 Hz), 7.60 (2H, d, J=8 hz), 8.18 (4H, d, J=8 Hz)

The compounds listed in Table 2 were obtained in substantially the samemanner as that of Example 21.

                  TABLE 2                                                         ______________________________________                                         ##STR44##                                                                    Example                                                                       No.    R.sup.a   R.sup.b R.sup.3                                                                            R.sup.c                                         ______________________________________                                        32     COOPNB    H       CH.sub.3                                                                            ##STR45##                                      33     "         PNZ     H                                                                                   ##STR46##                                      ______________________________________                                    

These compounds were immediately used as the starting compounds ofExamples 41 and 42, respectively.

EXAMPLE 34 ##STR47##

To a solution of 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(pyrrolidin-1-yl)methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(0.77 g) in acetone (8 ml) was added iodoacetamide (0.93 g) at ambienttemperature. The mixture was stirred overnight at the same temperature.The reaction mixture was evaporated in vacuo to give 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-(1-carbamoylmethylpyrrolidinio)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylateiodide (0.71 g).

IR (Nujol): 1760, 1710, 1690, 1605, 1520 cm⁻¹

NMR (CDCl₃ +DMSO-d₆, δ): 1.25 (3H, d, J=7 Hz), 1.27 (3H, d, J=7 Hz),1.80-2.50 (6H, m), 7.61 (2H, d, J=8 Hz), 7.82 (2H, d, J=8 Hz), 8.23 (2H,d, J=8 Hz), 8.27 (2H, d, J=8 Hz).

The compounds listed in Table 3 were obtained in substantially the samemanner as that of Example 2 or 48.

                                      TABLE 3                                     __________________________________________________________________________     ##STR48##                                                                    Example                                                                       No.  R.sup.a                                                                            R.sup.3                                                                          R.sup.c       data                                               __________________________________________________________________________    35   COOH CH.sub.3                                                                          ##STR49##    IR(Nujol): 1755-1745, 1660 cm.sup.-1 NMR(D.sub.                               2 O, δ): 1.20(3H, d, J=7Hz), 1.29(3H, d,                                J=7Hz), 1.50-2.05(2H, m), 2.37-2.96(6H, m),                                   3.20-3.58(8H, m) mp: >193° C. (dec.)        36   "    "                                                                                 ##STR50##    IR(Nujol): 1755-1735, 1590-1580 cm.sup.-1                                     NMR(D.sub.2 O, δ): 1.20(3H, d, J=7Hz),                                  1.38(3H, d, J=7Hz), 2.80(3H, s), mp:                                          >189° C. (dec.)                             37   "    "                                                                                 ##STR51##    IR(Nujol): 1755, 1695 cm.sup.-1 NMR(D.sub.2 O,                                δ): 1.33(3H, d, J=7Hz), 1.32(3H, d,                                     J=7Hz), 1.56-2.15(1H, m), 2.30-3.00(4H, m) SI                                 Mass: 412 (M.sup.+) mp: >191° C.                                       (dec.)                                             38   "    "                                                                                 ##STR52##    IR(Nujol): 1755, 1585 cm.sup.-1 NMR(D.sub.2 O,                                δ): 1.22(3H, d, J=6Hz), 1.30(3H, d,                                     J=6Hz), 1.75-2.35(5H, m) FB Mass: 4.26                                        (M.sup.+)                                          39   COOH CH.sub.3                                                                          ##STR53##    IR(Nujol): 1750, 1680-1650, 1580 cm.sup.-1                                    NMR(D.sub.2 O, δ): 1.20(3H, d, J=7Hz),                                  1.27(3H, d, J=7Hz), 1.52-2.10(1H, m), 2.75(3H,                                s). FB Mass: 425 (M.sup.+ +1) mp: 178°                                 C. (dec.)                                          40   "    H                                                                                 ##STR54##    IR(Nujol): 1770-1740, 1650, 1640 cm.sup.-1                                    NMR(D.sub.2 O, δ): 1.26(3H, d, J=7Hz),                                  1.50-1.80(1H, m), 2.50-3.03(8H,                                               m), 3.05-3.50(6H, m), 3.53-4.38(6H, m)             41   COO.sup.-                                                                          CH.sub.3                                                                          ##STR55##    IR(Nujol): 1755-1730, 1660-1640, 1590-1580                                    cm.sup.-1 NMR(D.sub.2 O, δ): 1.22(3H, d,                                J=7Hz), 1.33(3H, d, J=7Hz), 1.42-1.75(1H, m),                                 3.29(3H, s), 4.16-4.40(2H, m) SI Mass: 425                                    (M.sup.+) mp: >194° C. (dec.)               42   COO.sup.-                                                                          H                                                                                 ##STR56##    IR(Nujol): 1755, 1580-1570 cm.sup.-1 NMR(D.sub.                               2 O, δ): 1.26(3H, d, J=7Hz),                                            1.35-1.85(1H, m), 3.28(3H, s), SI Mass: 411                                   (M.sup.+) mp: >182° C. (dec.)               43   COO.sup.-                                                                          CH.sub.3                                                                          ##STR57##    IR(Nujol): 1750, 1660-1645, 1585 cm.sup.-1                                    NMR(D.sub.2 O, δ): 1.20(3H, d, J=7Hz),                                  1.27(3H, d, J=7Hz), 1.53-1.96(1H,                                             m), 2.10-2.43(4H, m), 2.50-2.90(1H, m),                                       3.26-3.57(2H, m) mp: 197° C.                __________________________________________________________________________                               (dec.)                                         

The following compound was obtained in substantially the same manner asthat of Example 2.

EXAMPLE 44 ##STR58##

mp: >171° C. (dec.)

IR (Nujol): 1760-1740, 1670-1650 cm⁻¹

NMR (D₂ O, δ): 1.22 (3H, d, J=7 Hz), 1.28 (3H, d, J=7 Hz), 1.55-1.96(2H, m), 2.50-2.93 (1H, m), 3.20-4.33 (17H, m)

FB Mass: 455 (M⁺ +1)

EXAMPLE 45 ##STR59##

To a solution of allyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-(2,5-dioxoimidazolidin-1-yl)-methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(1.44 g) in tetrahydrofuran (30 ml) were added triphenylphosphine (0.29g), sodium 2-ethylhexanoate (0.41 g) andtetrakis(triphenylphosphine)palladium(0) (0.13 g) successively withstirring at ambient temperature. After stirring at the same temperaturefor 1 hour, the reaction mixture was evaporated in vacuo to give aresidue. A mixture of the residue, 20% palladium hydroxide on carbon(0.5 g), 0.1M phosphoric acid buffer (pH 5.8, 60 ml) and tetrahydrofuran(60 ml) was stirred for 5 hours under atmospheric pressure of hydrogenat ambient temperature. After the catalyst was filtered off, thefiltrate was evaporated in vacuo to remove the organic solvent. Theresidue was chromatographed on nonionic adsorption resin, "Diaion HP-20"(Trademark, made by Mitsubishi Chemical Industries)(30 ml) eluting inturn with water (80 ml) and 5% aqueous acetone (90 ml). The fractionscontaining the desired compound were collected and lyophilized to give(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-2-(2,5-dioxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid (0.40 g).

mp: >195° C. (dec.)

IR (Nujol): 1755, 1710, 1580 cm⁻¹

NMR (D₂ O, δ): 1.20 (3H, d, J=7 Hz), 1.30 (3H, d, J=7 Hz), 1.53-1.98(1H, m), 2.53-2.96 (1H, m), 3.12-4.38 (13H, m)

FB Mass: 425 (M³⁰ +1)

EXAMPLE 46 ##STR60##

(4R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-4-methyl-7-oxo-3-[(2S,4S)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid was obtained byreacting allyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(2-oxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatein substantially the same manner as that of Example 48.

mp: >184° C. (dec.)

IR (Nujol): 1760, 1690-1680, 1590, 1280 cm⁻¹

NMR (D₂ O, δ): 1.21 (3H, d, J=7 Hz), 1.28 (3H, d, J=6 Hz), 1.50-2.15(2H, m) 2.50-2.93 (1H, m), 3.20-4.35 (13H, m)

SI Mass: 411 (M⁺ +1)

EXAMPLE 47 ##STR61##

Allyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl-4-methyl-3-[(2S,4S)-2-(4-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]thio-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate was obtained in 66.7% yield insubstantially the same manner as that of Example 1.

IR (Neat): 1770, 1710-1690, 1525 cm⁻¹

NMR (CDCl₃, δ): 1.03-1.46 (9H, m), 1.73-2.10 (2H, m), 2.32-2.70 (2H, m),2.73-3.86 (8H, m), 3.90-4.36 (4H, m), 4.50-4.95 (3H, m), 5.10-5.55 (4H,m), 5.70-6.20 (1H, m), 7.55 (2H, d., J=8 Hz), 8.19 (2H, d, J=8 Hz)

EXAMPLE 48 ##STR62##

To a solution of allyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-2-(4-methyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]-thio-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(2.45 g) in tetrahydrofuran (50 ml) were added triphenyl phosphine (0.50g), sodium 2-ethyl hexanoate (0.70 g) andtetrakis(triphenylphosphine)palladium(0) (0.22 g) successively withstirring at ambient temperature. After stirring at the same temperaturefor 1 hour, the reaction mixture was evaporated in vacuo to give aresidue. A mixture of the residue, 20% palladium hydroxide on carbon(0.5 g), 0.1M phosphoric acid buffer (pH=6.0, 80 ml) and tetrahydrofuran(80 ml) was stirred for 5 hours under atmospheric pressure of hydrogenat ambient temperature. After the catalyst was filtered off, thefiltrate was evaporated in vacuo to remove the organic solvent. Theresidue was chromatographed on nonionic adsorption resin, "Diaion HP-20"(trademark, made by Mitsubishi Chemical Industries) (30 ml) eluting inturn with water (90 ml) and 5% aqueous acetone (100 ml). The fractionscontaining the desired compound were collected and lyophilized to give(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-2-(4-methyl-2-oxoimidazolidin-1-yl)-methylpyrrolidin-4-yl]thio-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2-carboxylicacid (0.29 g).

mp: >183° C. (dec.)

IR (Nujol): 1760-1740, 1680-1650, 1580 cm⁻¹

NMR (D₂ O, δ): 1.00-1.40 (9H, m), 1.54-2.15 (1H, m), 2.50-2.95 (2H, m),3.00-4.40 (13H, m)

FB Mass: 425 (M⁺)

EXAMPLE 49 ##STR63##

4-Nitrobenzyl(4R,5S,6S)-3-[(2S,4S)-2-(3-ethyl-2-oxoimidazolidin-1-yl)methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidin-4-yl]thio-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 71.1% yield in substantially the same manner as that ofExample 1.

IR (Neat): 1770, 1710-1690, 1610, 1525, 1495 cm⁻¹

NMR (CDCl₃, δ): 1.06 (3H, t, J=7 Hz), 1.26 (3H, d, J=7 Hz), 1.34 (3H, d,J=7 Hz), 1.80-2.75 (5H, m), 3.10-3.90 (10H, m), 3.88-4.42 (4H, m),5.12-5.65 (4H, m), 7.56 (2H, d, J=9 Hz), 7.66 (2H, d, J=9 Hz), 8.25 (4H,d, J=9 Hz)

EXAMPLE 50 ##STR64##

(4R,5S,6S)-3-[(2S,4S)-2-(3-Ethyl-2-oxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid was obtained in 76.8% yield in substantially the same manner asthat of Example 2.

IR (Neat): 1770, 1690, 1635, 1500 cm⁻¹

NMR (D₂ O, δ): 1.08 (3H, t, J=7 Hz), 1.22 (3H, d, J=7 Hz), 1.30 (3H, d,J=6 Hz), 1.58-2.03 (1H, m), 2.53-2.94 (1H, m), 3.06-4.34 (16H, m)

FB Mass: 439 (M⁺ +1)

EXAMPLE 51 ##STR65##

To a solution of 4-nitrobenzyl(4R)-2-diazo-4-[(2R,3S)-3-{(1R)-1-hydroxyethyl}-4-oxoazetidin-2-yl]-3-oxopentanoate(1.0 g) in dichloroethane (10 ml) was added rhodium(II) octanoate (10mg) under refluxing. After refluxing for 30 minutes, the reactionmixture was cooled and evaporated in vacuo to give a residue. Theresidue was dissolved in benzene (5 ml) and then evaporated in vacuo togive 4-nitrobenzyl(4R,5R,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3,7-dioxo-1-azabicyclo[3.2.0]-heptane-2-carboxylate.

The compound obtained above was dissolved in acetonitrile (10 ml) andcooled to 0° C.˜2° C. under atmosphere of nitrogen. To this solutionwere added diphenyl phosphorochloridate (0.56 ml) andN,N-diisopropyl-N-ethylamine (0.49 ml) successively and the mixture wasstirred at the same temperature for 40 minutes. To the resultingsolution were added dropwise a solution of(2S,4S)-4-mercapto-1-methyl-2-(2-oxoimidazolidin-1-yl)methylpyrrolidine(0.60 g) in acetonitrile (6 ml) and N,N-diisopropyl-N-ethylamine (0.49ml) with stirring at 0°˜2° C., and the mixture was stirred at the sametemperature for 2 hours.

To a reaction mixture was added ethyl acetate (50 ml) and the solutionwas washed twice with aqueous sodium chloride, dried over anhydrousmagnesium sulfate and evaporated in vacuo. The resulting residue waschromatographed on silica gel (100 g) eluting with a mixture ofchloroform and methanol (19:1 V/V). The fractions containing the desiredcompound were collected and evaporated in vacuo to give 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1-methyl-2-(2-oxoimidazolidin-1-yl)methylpyrrolidin4-yl]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(0.49 g).

IR (Nujol): 1760, 1670, 1590, 1520, 1345 cm⁻¹

NMR (CDCl₃, δ): 1.19 (3H, d, J=7 Hz), 1.32 (3H, d, J=7 Hz), 2.25 (3H,s), 5.17 (1H, d, J=14 Hz), 5.46 (1H, d, J=14 Hz), 7.62 (2H, d, J=9 Hz),8.18 (2H, d, J=9 Hz)

EXAMPLE 52 ##STR66##

To a solution of 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1-methyl-2-(2-oxoimidazolidin-1-yl)methylpyrrolidin-4-yl]thio-4-methyl-7-oxo-1-azabicyclo-[3.2.0]hept-2-ene-2-carboxylate(0.47 g) in acetone (5 ml) was added methyl iodide (0.52 ml) and themixture was stirred at ambient temperature for 7 hours. The resultingprecipitates were collected, washed with acetone (10 ml) and dried invacuo to give 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1,1-dimethyl-2-(2-oxoimidazolidin-1-yl)methyl-4-pyrrolidinio]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylateiodide (0.22 g).

NMR (DMSO-d₆, δ): 1.16 (3H, d, J=6 Hz), 1.17 (3H, d, J=8 Hz), 2.75-2.93(1H, m), 3.14 (3H, s), 3.16 (3H, s), 3.70-4.28 (6H, m), 5.12 (1H, d, J=5Hz), 5.32 (1H, d, J=14 Hz), 5.50 (1H, d, J=14 Hz), 7.72 (2H, d, J=8.5Hz), 8.25 (2H, d, J=8.5 Hz)

EXAMPLE 53 ##STR67##

A mixture of 4-nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1,1-dimethyl-2-(2-oxoimidazolidin-1-yl)methyl-4-pyrrolidinio]thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylateiodide (0.21 g), 20% palladium hydroxide on carbon (0.20 g), 0.1Mphosphoric acid buffer (pH 5.8, 10 ml) and tetrahydrofuran (10 ml) wasstirred for 5 hours under atmospheric pressure of hydrogen at ambienttemperature. After the catalyst was filtered off, the filtrate wasevaporated in vacuo to remove the organic solvent. The resulting aqueoussolution was washed twice with ethyl acetate (15 ml) and concentrated invacuo to remove the organic solvent. The residue was chromatographed onnonionic adsorption resin, Diaion HP-20 (20 ml) eluting in turn withwater (40 ml) and 5% aqueous acetone (60 ml). The fractions containingthe desired compound were collected and lyophilized to give(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-3-[(2S,4S)-1,1-dimethyl-2-(2-oxoimidazolidin-1-yl)methyl-4-pyrrolidinio]-thio-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(125 mg).

IR (Nujol): 1750-1740, 1670-1640, 1590, 1500, 1280 cm⁻¹

NMR (D₂ O, δ): 1.21 (3H, d, J=8 Hz), 1.28 (3H, d, J=7 Hz), 1.40-1.80(1H, m), 1.83-2.26 (1H, m), 2.24 (6H, s), 3.35-4.33 (13H, m)

FB Mass: 439 (M⁺)

Preparation 52-1)

A solution of L-alanine methyl ester hydrochloride (39.2 g) andpotassium cyanate (34.1 g) in tetrahydrofuran (300 ml) and water (150ml) was stirred at 50°-60° C. for 1 hour and then stirred at 100° C. for30 minutes. The reaction mixture was extracted with tetrahydrofuran (300ml) and a mixture of tetrahydrofuran (20 ml) and water (100 ml). Theextract was washed with aqueous sodium chloride, dried over anhydrousmagnesium sulfate and evaporated in vacuo. The resulting residue waschromatographed on silica gel (200 g) eluting with a mixture ofchloroform and methanol (9:1 V/V). The fractions containing the desiredcompound were collected and evaporated in vacuo to give(4S)-4-methyl-2,5-dioxoimidazolidine (18.6 g).

NMR (CD₃ OD, δ): 1.35 (3H, d, J=7 Hz), 4.08 (1H, q, J=7 Hz)

Preparation 52-2)

(4R)-4-Methyl-2,5-dioxoimidazolidine was obtained quantitatively insubstantially the same manner as that of Preparation 52-1).

NMR (CD₃ OD, δ): 1.37 (3H, d, J=7 Hz), 4.12 (1H, q, J=7 Hz)

Preparation 53-1)

To a suspension of sodium borohydride (12.3 g) in tetrahydrofuran (180ml) was dropwise added boron trifluoride etherate (50 ml) underice-cooling and the mixture was stirred at the same temperature for 15minutes. To this solution was added a solution of(4S)-4-methyl-2,5-dioxoimidazolidine (18.6 g) in tetrahydrofuran (90 ml)under ice-cooling and the mixture was stirred at ambient temperatureovernight. To the solution was dropwise added methanol (100 ml) and themixture was filtered off. The filtrate was evaporated in vacuo. Theresulting residue was dissolved in methanol (200 ml) and conc.hydrochloric acid (5 ml). The solution was allowed to stand at ambienttemperature overnight. The reaction mixture was evaporated in vacuo andthe resulting residue was chromatographed on silica gel (200 g) elutingwith a mixture of chloroform and methanol (19:1 V/V). The fractionscontaining the desired compound were collected and evaporated in vacuoto give (4S)-4-methyl-2-oxoimidazolidine (12.21 g).

NMR (CDCl₃, δ): 1.25 (3H, d, J=7 Hz), 3.06 (1H, t, J=7 Hz), 3.58 (1H, t,J=7 Hz), 3.90 (1H, q, J=7 Hz), 5.10-5.90 (2H, broad s)

Preparation 53-2)

(4R)-4-Methyl-2-oxoimidazolidine (11.58 g) was obtained in 38.6% yieldin substantially the same manner as that of Preparation 53-1).

mp: 90°-92° C.

NMR (CDCl₃, δ: ) 1.25 (3H, d, J=7 Hz), 3.02-3.10 (1H, m), 3.55-3.64 (1H,m), 3.82-3.96 (1H, m), 5.93 (2H, m)

EI Mass: 100 (M⁺)

Preparation 54-1)

(2S,4R)-4-Methanesulfonyloxy-2-[(4S)-4-methyl-2-oxoimidazolidin-1-yl]carbonyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidinewas obtained in 23.4% yield in substantially the same manner as that ofPreparation 18.

NMR (CDCl₃, δ): 1.30 (3H, d, J=6 Hz), 3.04 (3H, s), 7.45 (1H, d, J=8Hz), 7.52 (1H, d, J=8 Hz), 8.20 (2H, broad d, J=8 Hz)

Preparation 54-2)

(2S,4R)-4-Methanesulfonyloxy-2-[(4R)-4-methyl-2-oxoimidazolidin-1-yl]carbonyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine was obtained in29.7% yield in substantially the same manner as that of Preparation 18.

IR (Neat): 1725-1685, 1610, 1525, 1170 cm⁻¹

NMR (CDCl₃, δ): 1.13, 1.32 (3H, double d, J=7 Hz), 2.22-2.34 (1H, m),2.75-2.87 (1H, m), 3.07 (3H, s), 3.83-4.09 (4H, m), 5.06-5.37 (3H, m),5.66-5.83 (2H, m), 7.44-7.54 (2H, m), 8.17-8.25 (2H, m)

Preparation 55-1)

(2S,4R)-4-Methanesulfonyloxy-2-[(4S)-4-methyl-2-oxoimidazolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 43.9% yield in substantially the same manner as that ofPreparation 22.

IR (Neat): 1710-1670, 1605, 1525, 1495, 1270, 1175 cm⁻¹

NMR (CDCl₃, δ): 1.20 (3H, d, J=6 Hz), 2.21-2.49 (2H, m), 3.01 (3H, s),4.72-5.00 (1H, m), 5.23 (2H, s), 7.50 (2H, d, J=8 Hz), 8.20 (2H, d, J=8Hz)

Preparation 55-2)

(2S,4R)-4-Methanesulfonyloxy-2-[(4R)-4-methyl-2-oxoimidazolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 43.2% yield in substantially the same manner as that ofPreparation 22.

NMR (CDCl₃, δ): 1.19 (3H, d, J=6 Hz), 2.21-2.52 (2H, m), 3.02 (3H, s),5.24 (2H, broad s), 7.53 (2H, d, J=8 Hz), 8.28 (2H, d, J=8 Hz)

Preparation 56-1)

(2S,4S)-4-Acetylthio-2-[(4S)-4-methyl-2-oxoimidazolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 54.9% yield in substantially the same manner as that ofPreparation 23.

NMR (CDCl₃, δ): 1.20 (3H, d, J=6 Hz), 2.33 (3H, s), 5.22 (2H, broad s),7.53 (2H, d, J=8 Hz), 8.22 (2H, d, J=8 Hz)

Preparation 56-2)

2S,4S)-4-Acetylthio-2-[(4R)-4-methyl-2-oxoimidazolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 79.5% yield in substantially the same manner as that ofPreparation 23.

NMR (CDCl₃, δ): 1.23 (3H, d, J=5 Hz), 2.34 (3H, s), 5.22 (2H, s), 7.53(2H, d, J=8 Hz), 8.24 (2H, d, J=8 Hz)

Preparation 57-1)

(2S,4S)-4-Mercapto-2-[(4S)-4-methyl-2-oxoimidazolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 76.2% yield in substantially the same manner as that ofPreparation 24.

IR (Neat): 1720-1670, 1605, 1520, 1490 cm⁻¹

NMR (CDCl₃, δ): 1.21 (3H, d, J=6 Hz), 4.92 (1H, broad s), 5.23 (1H, s),7.50 (2H, d, J=8 Hz), 8.23 (2H, d, J=8 Hz)

EI Mass: 395 (M⁺ +1), 394 (M⁺), 361 (M⁺ -33)

Preparation 57-2)

(2S,4S)-4-Mercapto-2-[(4R)-4-methyl-2-oxoimidazolidin-1-yl]methyl-1-(4-nitrobenzyloxycarbonyl)-pyrrolidinewas obtained in 76.2% yield in substantially the same manner as that ofPreparation 24.

IR (Neat): 1710-1675, 1610, 1520 cm⁻¹ m), 2.33-2.72 (1H, m), 5.22 (2H,s), 7.52 (2H, d, J=8 Hz), 8.22 (2H, d, J=8 Hz)

EXAMPLE 54-1) ##STR68##

4-Nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-2-{(4S)-4-methyl-2-oxoimidazolidin-1-yl}methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]-thio-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 63.3% yield in substantially the same manner as that ofExample 1.

IR (Nujol): 1765, 1705, 1690, 1605, 1520 cm⁻¹

NMR (CDCl₃, δ): 1.20 (3H, d, J=6 Hz), 1.28 (3H, d, J=7 Hz), 1.36 (3H, d,J=7 Hz), 5.05-5.64 (4H, m), 7.53 (2H, d, J=8 Hz), 7.64 (2H, d, J=8 Hz),8.22 (4H, d, J=8 Hz)

EXAMPLE 54-2) ##STR69##

4-Nitrobenzyl(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-3-[(2S,4S)-2-{(4R)-4-methyl-2-oxoimidazolidin-1-yl}methyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidin-4-yl]-thio-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatewas obtained in 63.4% yield in substantially the same manner as that ofExample 1.

IR (Nujol): 1750, 1710, 1690-1670, 1515 cm⁻¹

NMR (CDCl₃, δ): 1.15 (3H, d, J=6 Hz), 1.27 (3H, d, J=6 Hz), 1.35 (3H, d,J=6 Hz), 5.19-5.53 (4H, m), 7.50-7.70 (4H, m), 8.21 (2H, d, J=7Hz), 8.22(2H, d, J=7 Hz)

EXAMPLE 55-1) ##STR70##

(4R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-4-methyl-3-[(2S,4S)-2-{(4S)-4-methyl-2-oxoimidazolidin-1-yl}-methylpyrrolidin-4-yl]thio-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2-crboxylicacid was obtained in 53.7% yield in substantially the same manner asthat of Example 2.

mp: 176°-181° C. (dec.)

IR (Nujol): 1755-1735, 1675-1650 cm⁻¹

NMR (D₂ O, δ): 1.22 (6H, d, J=6 Hz), 1.28 (3H, d, J=6 Hz), 2.50-2.92(2H, m)

FB Mass: 425 (M⁺)

EXAMPLE 55-2) ##STR71##

(4R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-4-methyl-3-[(2S,4S)-2-{(4R)-4-methyl-2-oxoimidazolidin-1-yl}-methylpyrrolidin-4-yl]thio-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid was obtained in 67.8% yield in substantially the same manner asthat of Example 2.

mp: >181° C. (dec.)

IR (Nujol): 1750, 1680-1660, 1580, 1270-1260 cm⁻¹

NMR (D₂ O, δ): 1.23 (6H, d, J=6 Hz), 1.29 (3H, d, J=6 Hz), 1.52-2.02(1H, m), 3.02-4.36 (13H, m)

FB Mass: 425 (M⁺)

What we claim is:
 1. A compound of the formula which is selected fromthe group consisting of the formula: ##STR72## and the formula:##STR73## wherein R⁴ is an aliphatic heterocyclic group selected fromthe group consisting of pyrrolidinyl, imidazolidinyl, pyrazolidinyl,piperidino, piperazinyl, morpholino, oxoimidazolidinyl,dioxoimidazolidinyl and piperazinyl protected with phenyl- ornitrophenyl-substituted lower alkoxycarbonyl, said aliphaticheterocyclic group being about to A at a heterocyclic nitrogen and beingunsubstituted or substituted up to 2 times with the same or differentmembers selected from the group consisting of amino, protected amino,carbamoyl, lower alkyl, oxo, lower alkylsulfonyl, hydroxy(lower)alkyl,and carbamoyl(lower)alkyl, said protected amino being protected with aprotecting group selected from the group consisting of lower alkanoyl,lower alkylsulfonyl, carbamoyl, N-methylcarbamoyl, N-ethylcarbamoyl,lower alkoxycarbonyl, lower alkenyloxycarbonyl, lower alkenoyl,cyclo(lower)alkanecarbonyl, C₆ -C₁₀ aroyl, N-(C₆ -C₁₀) arylcarbamoyl, C₆-C₁₀ arenesulfonyl, and phenyl(lower)alkoxycarbonyl, said protectinggroup being unsubstituted or substituted with a nitro group;R⁵ ishydrogen, lower alkyl or imino-protective group selected from the groupconsisting of lower alkanoyl, lower alkylsulfonyl, carbamoyl,N-methylcarbamoyl, N-ethylcarbamoyl, lower alkoxycarbonyl, loweralkenyloxycarbonyl, lower alkenoyl, cyclo(lower)alkanecarbonyl, C₆ -C₁₀aroyl, N-(C₆ -C₁₀) arylcarbamoyl, C₆ -C₁₀ arenesulfonyl, andphenyl(lower)alkoxycarbonyl, said imino-protective group beingunsubstituted or substituted with a nitro group; A is lower alkylene;and R⁷ is a mercapto-protective group selected from the group consistingof (C₆ -C₁₀)ar(lower)alkyl, di- and triphenyl(lower)alkyl and acylgroups selected from the group consisting of lower alkanoyl, loweralkylsulfonyl, carbamoyl, N-methyl carbamoyl, N-ethylcarbamoyl, loweralkoxycarbonyl, lower alkenyloxycarbonyl, lower alkenoyl,cyclo(lower)alkanecarbonyl, C₆ -C₁₀ aroyl, N-(C₆ -C₁₀) arylcarbamoyl, C₆-C₁₀ arenesulfonyl, and phenyl(lower)alkoxycarbonyl, said acyl groupbeing unsubstituted or substituted with a nitro group; and saltsthereof.
 2. A compound of claim 1, whereinR⁴ is imidazolidinyl,oxoimidazolidinyl, dioxoimidazolidinyl,[(lower)alkylsulfonyl]oxoimidazolidinyl, piperazinyl, N-acylpiperazinyl,(lower)alkylpiperazinyl, N-acyl(lower)alkylpiperazinyl, pyrrolidinyl,aminopyrrolidinyl, acylaminopyrrolidinyl, carbamoylpyrrolidinyl,piperidinyl, aminopiperidinyl, acylaminopiperidinyl,hydroxy(lower)alkylpyrrolidinyl, (lower)alkylpiperazinyl,carbamoylpiperazinyl, oxopiperazinyl, morpholinyl,[(lower)alkyl]oxoimidazolidnyl or[hydroxy(lower)alkyl]oxoimidazolidinyl, and R⁵ is hydrogen, lower alkylor acyl.
 3. A compound of claim 2, whereinR⁵ is hydrogen, lower alkyl,lower alkenyloxycarbonyl or phenyl(or nitrophenyl)(lower)alkoxycarbonyl,and R⁷ is lower alkanoyl, C₆ -C₁₀ aroyl or triphenyl(lower)alkyl.
 4. Acompound of claim 3, whereinR⁴ is imidazolidinyl, oxoimidazolidinyl,dioxoimidazolidinyl, [(C₁ -C₄)alkylsulfonyl]oxoimidazolidinyl,piperazinyl, N-phenyl(or nitrophenyl) (C₁ -C₄)alkoxycarbonylpiperazinyl,(C₁ -C₄)alkylpiperazinyl, N-phenyl(or nitrophenyl) (C₁-C₄)alkoxycarbonyl(C₁ -C₄)alkylpiperazinyl, pyrrolidinyl,aminopyrrolidinyl, phenyl (or nitrophenyl) (C₁-C₄)alkoxycarbonylaminopyrrolidinyl, carbamoylpyrrolidinyl, piperidinyl,aminopiperidinyl, phenyl (or nitrophenyl) (C₁-C₄)alkoxycarbonylaminopiperidinyl, hydroxy (C₁ -C₄)alkylpyrrolidinyl,(C₁ -C₄)alkylpiperazinyl, carbamoylpiperazinyl, oxopiperazinyl,morpholinyl, [(C₁ -C₄)oxoimidazolidinyl or [hydroxy(C₁ -C₄)alkyloxoimidazolidinyl, R⁵ is hydrogen, C₁ -C₄ alkyl, C₂ -C₄alkenyloxycarbonyl or phenyl(or nitrophenyl) (C₁ -C₄)alkoxycarbonyl, R⁷is C₁ -C₄ alkanoyl, C₆ -C₁₀ aroyl or triphenyl(C₁ -C₄)alkyl, and A is C₁-C₄ alkylene.
 5. A compound of claim 4, whereinR⁴ is imidazolidinyl,oxoimidazolidinyl, dioxoimidazolidinyl, [(C₁-C₄)alkylsulfonyl]oxoimidazolidinyl, piperazinyl, (C₁-C₄)alkylpiperazinyl, pyrrolidinyl, aminopyrrolidinyl,carbamoylpyrrolidinyl, piperidinyl, aminopiperidinyl, hydroxy(C₁-C₄)alkylpyrrolidinyl, (C₁ -C₄)alkylpiperazinyl, carbamoylpiperazinyl,oxopiperazinyl, morpholinyl, [(C₁ -C₄)alkyl]oxoimidazolidinyl,[hydroxy(C₁ -C₄)alkyl]oxoimidazolidinyl, R⁵ is hydrogen or C₁ -C₄ alkyl,and A is C₁ -C₄ alkylene.